388 Results
Thermochemistry : CalcMolarEnthalpy (5 Variations)   
(Assessment Material (1))
White phosphorus, P4, ignites in air to produce heat, light, and P4O10 according to the following reaction.

P4(s) + 5O2(g) P4O10(s)

If 67.2 g of P4 is burned,1620 kJ of energy is evolved. What is the molar enthalpy of combustion of P4 if the process was carried out under constant pressure?

Bonding : OrganicBondLength (10 Variations)   
(Assessment Material (1))
1-amino-2-naphthol-6-sulfonic acid is used as a photographic developer. The structure for this compound is shown below, although lone electron pairs are not shown. Which of the following bonds in the structure is the shortest?
Equilibrium : SolubilityPressTemp (16 Variations)   
(Assessment Material (1))
How does increasing the temperature change the solubility of nitrogen in water?
Biochemistry : ComplementaryDNA (20 Variations)   
(Assessment Material (1))
Determine the sequence of the complementary DNA strand for the following sequence. (Note: Complementary strands match up 5' ends to 3' ends.)
5'-TAATGAGT-3'
Thermochemistry : MassFromCalorimetry (2 Variations)   
(Assessment Material (1))
The table below lists the specific heat capacities of several metals and liquids.

SubstanceSpecific Heat Capacity
J/(g.oC)
SubstanceSpecific Heat Capacity
J/(g.oC)
Al0.902H2O4.18
Fe0.451C2H5 OH2.46
Cu0.383CCl40.861
Au0.128CCl2F2 0.598

In an experiment a block of aluminum was heated to 100oC and placed in 200 g of water at 25oC. If the final temperature of the system is 43oC, and no heat transfer to the surroundings occurred, what is the mass of the aluminum block?

Thermochemistry : CalcHHessLaw (8 Variations)   
(Assessment Material (1))
The industrial process for making sulfuric acid has three steps. Using the data given, calculate the enthalpy change for the overall reaction for the process (the equation is given below).

2S(s) + 3O2(g) + 2H2O(l)2H2SO4(l)

Data:

S(s) + O2(g) SO2(g) Hrxn = -296.83 kJ
2SO3(g)O2(g) + 2SO2(g) Hrxn = -198.2 kJ
SO3(g) + H2O(l)H2SO4(l) Hrxn = -227.72 kJ

Acids_and_Bases : BufferWeakWeak (14 Variations)   
(Assessment Material (1))
What mass of potassium bicarbonate (KHCO3) must be added to 500 mL of a 0.200 M carbonic acid solution to make a buffer with pH = 6.30?
Acids_and_Bases : CalcSolnpH (5 Variations)   
(Assessment Material (1))
Use this acid/base table to answer the question below.

Calculate the pH of a {x}M sodium acetate solution.

DO NOT use scientific notation
Enter your answer to two decimal places.
DO NOT enter units

Acids_and_Bases : BufferWeakStrong (7 Variations)   
(Assessment Material (1))
How many mL of a 2.50 M HCl solution must be added to 500 mL of a 0.150 M CO32- solution to make a buffer with pH = 10.00?
Acids_and_Bases : PercentDissociationKa (3 Variations)   
(Assessment Material (1))
Calculate the percent dissociation in a {x}M aqueous solution of the weak acid HA. (Ka = {y} x 10-4)

Enter your answer to ONE decimal place.
DO NOT use scientic notation.
DO NOT write in the units.

Acids_and_Bases : pHBufferCalc (4 Variations)   
(Assessment Material (1))
Calculate the pH of a buffer solution containing {x}M NH3 and {y}M NH4NO3.

Enter your answer to TWO decimal places.
DO NOT use scientific notation.
DO NOT enter units
        eg:     4.55

Acids_and_Bases : pHDilution (6 Variations)   
(Assessment Material (1))
What is the pH of a solution made by diluting {x} mL of {y} M HNO3(aq) to a total volume of 500 mL?

Enter your answer to two decimal places.
DO NOT use scientific notation

Acids_and_Bases : BufferingCapacity (20 Variations)   
(Assessment Material (1))
If a buffer is prepared using 0.75 mol CH3COOH and 0.45 mol CH3COO- in 1 liter of aqueous solution, is the buffering capacity of the solution great enough to maintain its pH if 10 g NaOH is added?
Acids_and_Bases : AcidicOrBasicSalt (20 Variations)   
(Assessment Material (1))
When dissolved in an aqueous solution, which of the following salts will yield an acidic solution?
Acids_and_Bases : AcidBaseProperties (10 Variations)   
(Assessment Material (1))
Which of the following are properties of HCl?
AcidBaseProducts (10 variations)   
(Assessment Material (1))
The following acid/base table may be useful in answering the question below.

What products will result when HSO4- is added to water? Complete and balance the reaction below.

HSO4- + H2O ?

Atoms,_Molecules_and_Ions : CompFromNanoPic (9 Variations)   
(Assessment Material (1))
__________ can be represented by the nanoscale diagram below.

Which of the following is the best choice to fill in the blank?

Biochemistry : Anomer (20 Variations)   
(Assessment Material (1))
Classify each of the following monosaccharides as the or anomer.
Kinetics : RxnProfileEaDeltaE (11 Variations)   
(Assessment Material (1))
Based on the reaction profile, what is the energy change for the reaction?
Stoichiometry : LimitingReagent (8 Variations)   
(Assessment Material (1))
The synthesis of urea by Frederich W??hler in 1825 began the decline of the idea that "organic" chemicals could only be made by living organisms as part of their biological processes.

AgOCN(aq) + NH4Cl(aq)AgCl(s) + NH2CONH2(aq)

If you perform this reaction and collect the following table of data, in which trial(s) is AgOCN clearly the limiting reactant?

Trial AgOCN used NH4Cl AgCl produced
1 20.4 mL 5.3 mL 2.4 g
2 20.3 mL 10.4 mL 4.3 g
3 20.6 mL 15.4 mL 6.2 g
4 20.5 mL 20.6 mL 8.2 g
5 20.4 mL 25.2 mL 10.2 g
6 20.3 mL 30.4 mL 10.3 g

The mL of AgOCN and NH4Cl are the initial amounts used, the mass of AgCl is how much was recovered from the reaction. (Hint: You do not need to do any calculations to answer this question.)

Thermodynamics : ThermoKinStability (4 Variations)   
(Assessment Material (1))
Compare white and grey tin, both of which exist as solid phases of tin near room temperature.

Phase Hof (kJ/mol) So (J/(K*mol))
white tin 0 51.5
grey tin -2.1 44.8

Which type of stability does each exhibit at 40 oC?

white tin {1:MULTICHOICE:kinetically stable#No, that's incorrect.~=thermodynamically stable#Correct!}

grey tin {1:MULTICHOICE:=kinetically stable#Correct!~thermodynamically stable#No, that's incorrect.}

Stoichiometry : SolnStoich (4 Variations)   
(Assessment Material (1))
You are working in a forensic lab and are given a blood sample from a suspected drunk driver and asked to determine the person's blood alcohol level. The legal limit is 0.08% by mass in most states. You use the following reaction in your determination, assuming only the ethanol (C2H5OH) in the blood sample will react with the dichromate.
16H+(aq) + 2Cr2O72-(aq) + C2H5OH(l)4Cr3+(aq) + 11H2(l) + 2CO2(g)

If 14.6 mL of 0.10 M K2Cr2O7 are needed to react completely with 28 g of blood, what is the blood alcohol level of the driver?

Stoichiometry : RxnTable (10 Variations)   
(Assessment Material (1))
Iron reacts with oxygen to form iron(III) oxide according to the following reaction.

4Fe(s) + 3O2(g)2Fe2O3(s)


Fe(s) O2(g) Fe2O3(s)
Initial Amount - - -
Change - - -
End Amount - - -

Complete the reaction table for a reaction mixture containing 12.0 moles of iron and 10.0 moles of oxygen, and select the true statement(s) from following list.

Stoichiometry : GivenMassCalcStMat (10 Variations)   
(Assessment Material (1))
Aspirin is a common analgesic. If you want to produce 250. mg of aspirin (C9H8O4) from the reaction of C7H6O3 and C4H6O3, what is the minimum amount of C7H6O3 that is needed?

2C7H6O3(s) + C4H6O3(l) 2C9H8O4(s) + H2O(l)

Acids_and_Bases : ProtonTransferRxn (20 Variations)   
(Assessment Material (1))
Write an equation to describe the proton transfer that occurs when the following acid is added to water: HSO4-
Enter the products in the space below using the following as an example:
What ions are present in an aqueous calcium nitrate solution?
Ca(NO3)2(aq) Ca2+(aq) + 2NO3-(aq)
In this case, the answer would be: Ca2+(aq) + 2NO3-(aq)
You should enter: Ca^(2+) + 2NO3^(-)
In other words, use the ^ to indicate superscripts; put charges in parentheses; and leave a space on either side of the + sign. Your answer must be an exact match for the computer to grade it correctly, so be careful.

What products will result when HSO4- is added to water?

Thermodynamics : ATPFromGlucose (8 Variations)   
(Assessment Material (1))
When glucose is oxidized in the human body it releases a lot of Gibbs free energy. Rather than waste this free energy, the body stores much of it in the form of ATP. The following reaction shows this process of storing some of the energy from glucose in ATP. This is an example of coupled reactions in a biological system.

The label on a can of Coke says that it contains 39 g of sugar. Assume that all of the sugar is glucose (even though it isn't), and calculate how many moles of ATP can be produced theoretically by the oxidation of 39.0 g of glucose.
Stoichiometry : CalcPercentPurity (4 Variations)   
(Assessment Material (1))
To test the purity of calcium sulfate, you dissolve a 4.56g sample in water and add oxalic acid to precipitate out calcium oxalate. If 3.45g of precipitate forms, what is the percent purity of the calcium sulfate?

CaSO4(aq) + H2C2O4(aq) CaC2O4(s) + H2SO4(aq)

Stoichiometry : CalcWtPercent (6 Variations)   
(Assessment Material (1))
A standard dose of antacid as a calcium supplement is two tablets. The active ingredient in many of these tablets is calcium carbonate. One tablet, having a weight of 1.415 g, is reacted with excess HCl(aq) to produce 0.22 g CO2. What is the weight percent of calcium in this tablet?

CaCO3(s) + 2HCl(aq)CaCl2(aq) + H2O(l) + CO2(g)

Special_Topics : RecycledProducts (15 Variations)   
(Assessment Material (1))
Use the EcoRecycle Information Sheets at the Ecorecycle Victoria Plastics Recycling website to answer the following question. (Scroll down to the table called "Some uses for plastics and recycled plastics in Australia".)

Which of the following products can be made from recycled polyethylene terephthalate (PET)?

NOTE: If the link above is no longer active, click here for the information.

Equilibrium : MoreMolesAtEquil (19 Variations)   
(Assessment Material (1))
The following reaction has an equilibrium constant of 0.050 at a given temperature.

N2(g)+ O2(g) 2NO(g)

If you have 0.75 moles of N2(g) and 0.75 moles of O2(g) in a 2.0L container initially, how many moles of N2 will be present when the system reaches equilibrium?

Equilibrium : ICETables (16 Variations)   
(Assessment Material (1))
2C2H2(g) + 5O2(g) 4CO2(g) + 2H2O(g)

You have 0.4 moles C2H2 and 0.2 moles O2 present initially in a 5L flask. You allow the reaction to run until it reaches equilibrium. Which of the following is the correct ICE table for this process?

Equilibrium : ConvertKcKp (6 Variations)   
(Assessment Material (1))
Nitrosyl bromide is formed from nitrogen oxide and bromine:

Kp for this reaction is {x} at {y}°C. Calculate Kc at this temperature. (R = 0.0821 L atm/mol K)

Note:
DO NOT use scientific notation
Use integers (no decimal places) even is this is not the correct number of significant figures.
DO NOT write in the units.
eg: 18

Equilibrium : CalcKc (4 Variations)   
(Assessment Material (1))
A container initially has {y} M ammonia at a certain temperature. When the system reaches equilibrium the concentration of ammonia is {x} M. Calculate Kc for the following reaction as written.

Note:
      Answers must be written using scientific notation with "e"
      DO NOT use spaces
      DO NOT write in the units.
      Be sure to use three significant figures.
          eg:       2.44e-5

Equilibrium : CalcKp (2 Variations)   
(Assessment Material (1))
In one experiment chemists studied the formation of phosgene, COCl2, by mixing {y} atm of carbon monoxide and {z} atm of Cl2 in a reaction vessel at 700K. After the system reached equilibrium, the total pressure was {x} atm. Calculate Kp for the reaction.

Hint: Remember that the total pressure is the sum of all the partial pressures.

Note:
      Do Not use scientific notation
      DO NOT use spaces
      DO NOT write in the units.
      Be sure to write your answer with only one decimal place even if this is not the correct number of significant figures.

Equilibrium : CalcRxnQuotient (13 Variations)   
(Assessment Material (1))
In an experiment, 4.44 mol of SO2, 7.93 mol of O2 and 4.03 mol of SO3 are placed in a 2.0L reaction vessel at a certain temperature. Calculate the reaction quotient, Q, for the reaction as written:

What is the calculated reaction quotient, Q? {2:NUMERICAL:=2.1e-1:1e-2#Correct! ~%50%2.1e-1:5e-2#Close but not quite right}

If Kc for this reaction at the temperature of the experiment is 3.7 x 103, will the reaction move toward the left or toward the right? {1:MULTICHOICE:left#Sorry, that's wrong.~=right#Correct!}

Thermodynamics : InterpretKandDeltaG (16 Variations)   
(Assessment Material (1))
The thermodynamic equilibrium constant for the following reaction is 0.15 at 1227°C.
2 SO2(g) + O2(g) 2 SO3(g)
Check the box for each true statement.
Stoichiometry : RxnMolsProduced (8 Variations)   
(Assessment Material (1))
Given the following balanced chemical reaction:
4A + 3B2 2A2B3
If 12 moles of A are reacted with excess B2, how many moles of A2B3 will be produced?
Very carefully enter the number below.
Stoichiometry : TheorYieldDeviation (10 Variations)   
(Assessment Material (1))
You reacted a known amount of phosphorous triiodide with excess water and determined that the percent yield of phosphoric acid was less than 100%, which of the following statements could explain why?
PI3 + 3H2O H3PO3 + 3HI
Stoichiometry : MolsO2ToReactFuel (10 Variations)   
(Assessment Material (1))
Butane can be used as a fuel. How many moles of oxygen are needed to completely react with 3.0 moles of butane?

The unbalanced reaction equation is given below:
C4H10(g) + O2(g) CO2(g) + H2O(g)

Stoichiometry : GivenYieldCalcStMat (4 Variations)   
(Assessment Material (1))
Calcium oxide and water are produced by heating calcium hydroxide. If the reaction has an expected yield of 60%, how much calcium hydroxide should be reacted to produce 115g of calcium oxide?

Ca(OH)2 CaO + H2O

Stoichiometry : DeterMolesInRxn (4 Variations)   
(Assessment Material (1))
The reaction of zinc with aqueous hydrochloric acid has the following unbalanced equation

Zn(s) + HCl(aq) ArrowZnCl2(aq) + H2(g)

When 0.1 moles of zinc is reacted with 0.1 moles of hydrochloric acid ...

Stoichiometry : CalcTheorYield (10 Variations)   
(Assessment Material (1))
If you react 6.2g of phosphine with 8.30g of oxygen, what is the theoretical yield of phosphorous pentaoxide?

4PH3 + 8O2 P4O10 + 6H2O

Solutions : CalcMolarityFromPPT (10 Variations)   
(Assessment Material (1))
You are given a water sample to analyze from a lake contaminated with lead. It takes 24 mL of 0.020 M NaCl to exactly precipitate the Pb2+ ions from 61 mL of the water sample. What is the concentration of Pb2+ ions in the water?
Pb2+(aq) + 2NaCl(aq)PbCl2(s) + 2Na+(aq)
Reactions : IDSampleRxnVideo (7 Variations)   
(Assessment Material (1))
You have an unknown aqueous sample. You add aqueous copper(II) sulfate to the sample. View the video below and determine which of the compounds listed below could be your sample.

Biochemistry : Tertiary (16 Variations)   
(Assessment Material (1))
Which of the following is NOT true about the tertiary structure of water-soluble proteins?
Biochemistry : PeptideStructure (3 Variations)   
(Assessment Material (1))
All amino acids have which pair of functional groups?
Biochemistry : Inhibitor (15 Variations)   
(Assessment Material (1))
Which of the following molecules would you expect to be the strongest competitive inhibitor of the enzyme whose substrate is shown?

alcohol dehydrogenase, substrate ethanol
CH2CH2OH

Biochemistry : BioElements (20 Variations)   
(Assessment Material (1))
Use the Web-Elements website to identify which of the following biologically important elements are important for nerve function.

(Once you have selected an element, you should scroll down the left frame until you see "element" around us and then select Biology. After you have selected biology once, that information will appear for all subsequent elements chosen.)

Biochemistry : ClassifyAminoAcid (20 Variations)   
(Assessment Material (1))
Determine whether the following amino acids have nonpolar, polar but neutral, acidic, or basic R groups.
Acids_and_Bases : SolnGrams (20 Variations)   
(Assessment Material (1))
How many grams of sodium hydroxide (NaOH) must be dissolved in 510 ml of water to make a solution with a pH = 8.1?
Intermolecular_Forces__Liquids_and_Solids : VaporPressure (10 Variations)   
(Assessment Material (1))
Which of the following statements is true?
Intermolecular_Forces__Liquids_and_Solids : VaporizeIntmolcForces (10 Variations)   
(Assessment Material (1))
What type(s) of intermolecular forces must be overcome when liquid hexane (CH3CH2CH2CH2CH2CH3) vaporizes?
Intermolecular_Forces__Liquids_and_Solids : Superconductors (4 Variations)   
(Assessment Material (1))
Which of the following statements is NOT an accurate description of superconducting materials?
Intermolecular_Forces__Liquids_and_Solids : PhaseEnergyChanges (6 Variations)   
(Assessment Material (1))
When a liquid is transformed into its vapor at constant temperature,
Intermolecular_Forces__Liquids_and_Solids : OrganicBoilingPoint (11 Variations)   
(Assessment Material (1))
Which of the following organic compounds has the highest boiling point?
Intermolecular_Forces__Liquids_and_Solids : LatticeEnergyMelting (8 Variations)   
(Assessment Material (1))
Which of these substances has the highest melting point?
Intermolecular_Forces__Liquids_and_Solids : IntermolecularForces (10 Variations)   
(Assessment Material (1))
For which of the following compounds is hydrogen bonding the strongest?
Intermolecular_Forces__Liquids_and_Solids : GeneralIntermolForces (8 Variations)   
(Assessment Material (1))
Which of the following statements about intermolecular forces is incorrect?
Intermolecular_Forces__Liquids_and_Solids : ElectricalConductivity (8 Variations)   
(Assessment Material (1))
Which of the following has the greatest electrical conductivity?
Intermolecular_Forces__Liquids_and_Solids : DensityFromUnitCell (13 Variations)   
(Assessment Material (1))
Oldhamite (CaS) has a rock salt structure like NaCl (which has interpenetrating face-centered cubic structures). The ionic radius of Ca2+ is 0.99 angstroms, and the ionic radius of S2- is 1.84 angstroms. What is the density of CaS?
Intermolecular_Forces__Liquids_and_Solids : PhaseDiagrams (6 Variations)   
(Assessment Material (1))
Match the following conditions to the physical state of the contents of the vessel.

Click here to open the phase diagram.

Intermolecular_Forces__Liquids_and_Solids : CanHBondsForm (8 Variations)   
(Assessment Material (1))
For which of the following substances will strong hydrogen bonds form between the molecules? (You may select more than one.)
Intermolecular_Forces__Liquids_and_Solids : BoilingPoint (10 Variations)   
(Assessment Material (1))
Which of the following substances has the highest boiling point?
Intermolecular_Forces__Liquids_and_Solids : AtomRadiusUnitCell (7 Variations)   
(Assessment Material (1))
Nickel has a unit cell that is face-centered cubic with a volume of 43.763Å3. The atom at the center of each face just touches the atoms at the corners. What is the atomic radius of nickel?
Intermolecular_Forces__Liquids_and_Solids : ClassifySolids (10 Variations)   
(Assessment Material (1))
Classify each of the following substances, in the solid state, as molecular, ionic, covalent network, or metallic.

Substance Appearance Melting Pt. (¬?C) Boiling Pt. (¬?C) Conducts as solid Conducts as liquid
A Colorless crystal -121 20.8 no no
B Colorless crystal 846 1505 no yes
C Silvery gray 1675 3260 yes yes
D Colorless crystal 1713 2590 no no

Atoms,_Molecules_and_Ions : NameIonFromFormula (16 Variations)   
(Assessment Material (1))
The name of NH4+ is the __________ ion.

Write the name of the ion in the box below. Be careful, spelling counts.

Atoms,_Molecules_and_Ions : CalcMolarMass (8 Variations)   
(Assessment Material (1))
What is the molar mass of potassium phosphate, K3PO4?

Enter the numeric value very carefully below, rounding to one decimal place only. Do not put the units in, but think about what the units are!

Atoms,_Molecules_and_Ions : NameIsotope (10 Variations)   
(Assessment Material (1))
Which of the following represents an atom that has 19 protons, 19 electrons, and 21 neutrons?
Atoms,_Molecules_and_Ions : NameFromFormula (16 Variations)   
(Assessment Material (1))
What is the name of N2H4?
Atoms,_Molecules_and_Ions : MassInAlloy (10 Variations)   
(Assessment Material (1))
Gold is alloyed with other metals to make it less malleable. 10 karat gold is an alloy that is 41.7% gold. How much pure gold is in a 20. gram 10 karat gold ring?
Atoms,_Molecules_and_Ions : IonType (8 Variations)   
(Assessment Material (1))
Identify the following ion as monatomic or polyatomic and as an anion or a cation: Cr2O7-2
Atoms,_Molecules_and_Ions : IonicProperties (8 Variations)   
(Assessment Material (1))
Which of the following statements concerning the properties of ionic compounds is NOT correct?
Atoms,_Molecules_and_Ions : IonicName (10 Variations)   
(Assessment Material (1))
What is the name of MgS?
Atoms,_Molecules_and_Ions : IonicFormula (10 Variations)   
(Assessment Material (1))
Which pair of ions will form a compound of formula M2X?
Atoms,_Molecules_and_Ions : IonChargeSubatmParts (10 Variations)   
(Assessment Material (1))
What is the charge on an ion that contains 47 protons, 62 neutrons, and 46 electrons?
Atoms,_Molecules_and_Ions : GeneralSubatmParts (7 Variations)   
(Assessment Material (1))
Which two of the subatomic particles have equal, but opposite, charges?
Atoms,_Molecules_and_Ions : GeneralPeriodicTable (12 Variations)   
(Assessment Material (1))
Which of the following statements concerning the periodic table is NOT correct?
Atoms,_Molecules_and_Ions : ElemtAndSubatmParts (10 Variations)   
(Assessment Material (1))
Give the number of electron, protons, and neutrons in an atom of 14C.
Atoms,_Molecules_and_Ions : ElementSpelling (10 Variations)   
(Assessment Material (1))
Which of the following elements are spelled incorrectly?
Atoms,_Molecules_and_Ions : ElementGroup (10 Variations)   
(Assessment Material (1))
The element neon is ...
Atoms,_Molecules_and_Ions : CompareParticles (20 Variations)   
(Assessment Material (1))
Which has the greater number of particles, 1 mol O2 or 1 mol O?
Atoms,_Molecules_and_Ions : CompareElements (10 Variations)   
(Assessment Material (1))
Which of the following is something that nitrogen and antimony have in common?
Atoms,_Molecules_and_Ions : CalcAtmWeight (10 Variations)   
(Assessment Material (1))
Chlorine has two naturally occurring isotopes, 35Cl and 37Cl, with masses of 34.9689 amu and 36.9659 amu, respectively. Calculate the abundances of these isotopes of chlorine.
Atoms,_Molecules_and_Ions : BinaryMolcFromImage (8 Variations)   
(Assessment Material (1))
Which of the following binary compounds could the figure below best represent?

Atoms,_Molecules_and_Ions : AtomicRatio (10 Variations)   
(Assessment Material (1))
Which compound(s) contain the most nitrogen atoms per molecule or formula unit?
Atoms,_Molecules_and_Ions : AllotropesOfElement (4 Variations)   
(Assessment Material (1))
Which of the following is an allotrope of oxygen? (You may select more than one.)
Atoms,_Molecules_and_Ions : IonicOrMolecular (10 Variations)   
(Assessment Material (1))
Identify each of the following compounds as ionic or molecular.
Atoms,_Molecules_and_Ions : IonCharge (12 Variations)   
(Assessment Material (1))
Identify each of the following ions as having the correct or incorrect charge.
Atoms,_Molecules_and_Ions : DescrSubatmParts (8 Variations)   
(Assessment Material (1))
Identify each of the following statements as describing a proton, neutron, or electron.
Atomic_Structure_and_the_Periodic_Table : Isoelectronic (4 Variations)   
(Assessment Material (1))
Which of the following atoms or ions does NOT have an electron configuration of [He]2s22p6?
Atomic_Structure_and_the_Periodic_Table : IonizationEnerTrends (10 Variations)   
(Assessment Material (1))
Which of the following groups of elements is arranged correctly in order of increasing first ionization energy?
Atomic_Structure_and_the_Periodic_Table : GeneralPeriodicTrends (5 Variations)   
(Assessment Material (1))
Which of the following statements is an INCORRECT description of periodic trends for main group elements?
Atomic_Structure_and_the_Periodic_Table : GeneralOrbitals (4 Variations)   
(Assessment Material (1))
Which of the following statements about orbitals in multi-electron atoms is CORRECT?
Atomic_Structure_and_the_Periodic_Table : ExplainPeriodicTrends (10 Variations)   
(Assessment Material (1))
In an isoelectronic series the ionic radii...
Atomic_Structure_and_the_Periodic_Table : EnergyInEinstein (10 Variations)   
(Assessment Material (1))
Calculate the energy of one mole of photons (an Einstein) for the 589 nm yellow line of the sodium spectrum.
Atomic_Structure_and_the_Periodic_Table : CorrectBoxDiagram (10 Variations)   
(Assessment Material (1))
Which of the following orbital box diagrams is correct?
Atomic_Structure_and_the_Periodic_Table : CompareRadii (10 Variations)   
(Assessment Material (1))
Which of the following have larger radii than a fluorine atom?
Atomic_Structure_and_the_Periodic_Table : CompareEMRadiation (12 Variations)   
(Assessment Material (1))
Which of the following have photons with less energy than those of blue light?
Atomic_Structure_and_the_Periodic_Table : CompareElectConfigs (8 Variations)   
(Assessment Material (1))
Compare the following two elements, identified by their electron configurations:

A - [Kr]4d95s2
B - [Ar]3d104s24p4

Select the answer(s) that has the correct comparison between elements.

Atomic_Structure_and_the_Periodic_Table : ColorFromFrequency (10 Variations)   
(Assessment Material (1))
According to the electromagnetic spectrum, what color is light that has a frequency of 6.95x1014Hz?
Atomic_Structure_and_the_Periodic_Table : AtomicNumElecConfig (10 Variations)   
(Assessment Material (1))
An element X has atomic number 13. Which of the following statements about the electron configuration of X is correct?
Atomic_Structure_and_the_Periodic_Table : ValenceTotalElectrons (10 Variations)   
(Assessment Material (1))
Given the following electron configuration:
1s22s22p63s2
1. How many total electrons are in this species? {1:SHORTANSWER:~=12}

2. How many valence electrons are in this species? {1:SHORTANSWER:~=2}

Atomic_Structure_and_the_Periodic_Table : MatchElectronConfig (10 Variations)   
(Assessment Material (1))
Match the following electron configurations to the correct atoms or ions. Possible choices are: Br, Ca, Cl-, Mg2+, Mn, and Ti2+.
Thermochemistry : HeatTransfers (10 Variations)   
(Assessment Material (1))
A red-hot piece of lead is dropped into water. Which of the following statements are true? (Assume that there are no energy transfers between anything except the lead and the water.)
Thermochemistry : HeatCapacitySolLiq (4 Variations)   
(Assessment Material (1))
The Table below lists the specific heat capacities of several metals and liquids.

Substance Specific Heat Capacity
J/(g.oC)
Substance Specific Heat Capacity
J/(g.oC)
Al 0.902 H2O 4.18
Fe 0.451 C2H5OH 2.46
Cu 0.383 CCl4 0.861
Au 0.128 CCl2F2 0.598

In an experiment, 50 g of a metal was heated to 100oC and placed in 200 g of a liquid at 25oC. Which of the following combinations of metal and liquid will produce the largest temperature increase in the liquid? (Assume that there is no transfer of energy to the surroundings.)

Electrochemistry : BatteryDesign (8 Variations)   
(Assessment Material (1))
Students are attempting to construct a battery in the laboratory that will light up a light bulb. Compare the following lists prepared by students and determine which student will not be able to successfully build a "battery" that will light up the bulb.
Electrochemistry : BalanceRedoxRxn (20 Variations)   
(Assessment Material (1))
The following electrochemical data may be helpful in answering the question below.

Magnesium reacts with nitric acid to form magnesium nitrate and nitrogen monoxide in an acidic aqueous solution. Write the balanced equation for this reaction.

Electrochemistry : FuelCellsAndBatteries (20 Variations)   
(Assessment Material (1))
Determine whether the following descriptions are characteristic of fuel cells, primary batteries, secondary batteries or both batteries and fuel cells.
Bonding : ResonanceStructures (10 Variations)   
(Assessment Material (1))
Select the molecule(s) below for which resonance structures can be drawn.
Bonding : OctetRuleExceptions (10 Variations)   
(Assessment Material (1))
For which of the following atoms are exceptions to the octet rule possible?
Bonding : MostPolarBond (8 Variations)   
(Assessment Material (1))
From the bonds listed below, choose the one that is the most polar. (Try to predict electronegativity differences based on positions of the bonded atoms in the periodic table.)
Bonding : LewisStructures (10 Variations)   
(Assessment Material (1))
Which of the following Lewis structures are CORRECT?
Bonding : ImpossibleStructure (10 Variations)   
(Assessment Material (1))
Which of the following formulas represent substances that are likely to be stable at ordinary temperature and pressure? A good way to decide is to ask for which of the formulas is it possible to draw a reasonable Lewis structure (one that obeys the usual rules for drawing Lewis structures)?
Bonding : GeneralResonIsomer (4 Variations)   
(Assessment Material (1))
Which of the following statements is true?
Bonding : EnergyBreakAllBonds (10 Variations)   
(Assessment Material (1))
Use the bond energies given in to determine the total energy needed to break all of the bonds in C3H6. (Do not use ring structures.)
Bonding : Electronegativity (8 Variations)   
(Assessment Material (1))
From the bonds listed below, choose the one in which the highlighted atom is the partially positive end of the bond. (Try to predict electronegativity differences based on positions of the bonded atoms in the periodic table.)
Bonding : DetermineStructure (8 Variations)   
(Assessment Material (1))
H A substance is analyzed and found to contain 57.10% carbon, 4.80% hydrogen and 38.06% oxygen by weight. Its molecular weight is determined to be 126.11 g/mol. Which of the structures shown are possible structures for the substance?
Bonding : CompareBondLength (5 Variations)   
(Assessment Material (1))
Which of the following compounds has the shortest bond between nitrogen and oxygen?
Bonding : ValenceElectrons (10 Variations)   
(Assessment Material (1))
Determine the number of valence electrons for each molecule or ion and match it with the number in the pull-down list to the right of the formula.
Bonding : MatchBondStrength (8 Variations)   
(Assessment Material (1))
Match each of the following molecules to the best energy value for each bond. Do not use the table of bond energies in your book, but predict these values using your knowledge of bond length and bond strength.
Possible energies are: 300 kJ/mol, 330 kJ/mol, 415 kJ/mol and 950 kJ/mol.
Bonding : IonicOrCovalent (10 Variations)   
(Assessment Material (1))
Match the following formulas to the correct type of bonding: ionic or covalent.
Biochemistry : Secondary (15 Variations)   
(Assessment Material (1))
What secondary structure element is represented by the green sequence in the following structure of the protein calmodulin?

JMOLSCRIPT{reset; spacefill off; cpk off; set background white; wireframe off; ribbons; select 102-112; color [0,255,0]}

Biochemistry : StructureDef (4 Variations)   
(Assessment Material (1))
What kind of structure is defined by the linear sequence of amino acids in the protein chain?
Biochemistry : Replication (8 Variations)   
(Assessment Material (1))
Which of the following is NOT a feature of replication?
Biochemistry : PeptideSequence (19 Variations)   
(Assessment Material (1))
Use the amino acid table below to answer the following question.

Which of the following structures corresponds to the peptide Met-Thr-Arg (methionylthreonylarginine)?

Biochemistry : NotCarb (16 Variations)   
(Assessment Material (1))
Which of the following is NOT a function of carbohydrates in the cell?
Biochemistry : LocateAminoAcid (4 Variations)   
(Assessment Material (1))
Where would you expect to find a proline unit in the structure of a water-soluble globular protein? Why?

Biochemistry : IDGroupType (4 Variations)   
(Assessment Material (1))
Identify the R-group that would result in an amino acid that would fit in the hydrophobic category.
Biochemistry : MeltPoint (20 Variations)   
(Assessment Material (1))
Which of the following molecules will have the highest melting point?
Biochemistry : EnzymesCan (12 Variations)   
(Assessment Material (1))
Which of the following is something that enzymes CANNOT do?
Biochemistry : LipidRole (10 Variations)   
(Assessment Material (1))
Which aspect of the structure of a phospholipid is most directly responsible for its role as a source of some vitamins?
Biochemistry : Carbform (20 Variations)   
(Assessment Material (1))
Which of the following molecules could be a carbohydrate?
Biochemistry : Bilayer (20 Variations)   
(Assessment Material (1))
Which of the following species would you expect to be able to cross a lipid bilayer?
Biochemistry : Amphiphile (20 Variations)   
(Assessment Material (1))
Which of the following molecules is an amphiphile?
Acids_and_Bases : ChooseIndicator (8 Variations)   
(Assessment Material (1))

A 25.0 mL aliquot of a 1.44M solution of ammonia (Kb = 1.8 x 10-5) is titrated with 1.50M HCl. Use the Indicator Table below to decide which of the indicators listed would most accurately signal the equivalence point for this titration.

Write the letter corresponding to your choice of indicator in the box.

Acids_and_Bases : WeakStrongAcidPics (11 Variations)   
(Assessment Material (1))
Which diagram best represents an aqueous solution of HCl? (Water is not shown.)

Acids_and_Bases : WeakAcidSolnpH (20 Variations)   
(Assessment Material (1))
Given an aqueous solution of 0.30 M acetic acid (Ka = 1.8 x 10-5), the pH is approximately ...
Acids_and_Bases : WaterAutoIonization (20 Variations)   
(Assessment Material (1))
What effect will the addition of H2CO3 have on the autoionization of water?

Acids_and_Bases : ReactProductFavored (20 Variations)   
(Assessment Material (1))
You may want to use the following acid/base table to answer the question below.

Which of the following reactions will be product -favored?

Acids_and_Bases : PracticalAcidBase (20 Variations)   
(Assessment Material (1))
Which of the following statements is true?
Acids_and_Bases : LewisAcidBaseRxns (19 Variations)   
(Assessment Material (1))
Identify the Lewis Acid and Base in the reaction of Ag+ and NH3 to form Ag(NH3)2+
Acids_and_Bases : IDLewisAcidBase (20 Variations)   
(Assessment Material (1))
Which of the following is a Lewis acid?
Acids_and_Bases : HendersonHassel (20 Variations)   
(Assessment Material (1))
You may want to use the following acid/base table to answer the question below.

Papain is a thiol protease isolated from papaya. The optimal pH for its enzymatic activity is 6.0-7.0. Which of the following buffering systems would work best for a laboratory experiment requiring active papain at pH 6.5? What molar ratios of the compounds would you use to prepare the solution?

Thermodynamics : ProbabilityEnergyDist (23 Variations)   
(Assessment Material (1))
Consider a system that has two indistinguishable molecules that can occupy three different energy levels (having energies of 1kJ, 2kJ and 3kJ, respectively). What is the probability that the molecules will have a total energy of 2 kJ?
Thermodynamics : GeneralThermo (6 Variations)   
(Assessment Material (1))
Which of the following statements is an inaccurate statement about thermodynamics?
Thermodynamics : EntropyPhaseChange (13 Variations)   
(Assessment Material (1))
Aluminum can be evaporated in a vacuum to form highly reflective coatings. Aluminum boils at 2792K and has a heat of vaporization of 70.0 kcal/mol. Calculate the entropy change for the vaporization of one mole of aluminum.
Thermodynamics : ConservGibbsEnergy (6 Variations)   
(Assessment Material (1))
Which of the following best illustrates conservation of Gibbs free energy?
Thermodynamics : PredictEntropyChange (10 Variations)   
(Assessment Material (1))
For each of the following processes, indicate whether you expect the entropy change of the system to be positive or negative.
Thermodynamics : CompareEntropyQual (16 Variations)   
(Assessment Material (1))
Indicate which substance in each of the following pairs of substances you expect to have higher entropy. Assume that you have a mole of each substance and all substances are at the same temperature.
Thermochemistry : ThermalEnergy (2 Variations)   
(Assessment Material (1))
The sketch below shows two identical flasks with different volumes of water at the same temperature. Which of the following is true?
Thermochemistry : PhaseChanges (8 Variations)   
(Assessment Material (1))
Steam at 100oC is condensed by an ice-water mixture at 0oC. Assuming that there is still ice present when the process is over, how much ice will be melted if 10.0 g of steam is condensed? The following may be useful:
enthalpy of vaporization of water = 40.7 kJ/mol; enthalpy of fusion of water = 6.07 kJ/mol; specific heat capacity of water = 4.184 J/g•K.
Thermochemistry : PhaseChangeEnthalpy (10 Variations)   
(Assessment Material (1))
A solid melts to a liquid. Which of the following statements are true? (Assume constant pressure and a flexible container.)
Kinetics : FactorsAffectingRate (7 Variations)   
(Assessment Material (1))
Which of the following changes would NOT affect the rate of the reaction of cisplatin with water?
Pt(NH3)2Cl2(aq) + H2O(l) [Pt(NH3)2(H2O)Cl]+ + Cl-
Kinetics : ElementRxnRateLaws (13 Variations)   
(Assessment Material (1))
Assume that the equation below represents an elementary reaction. Predict the rate expression (rate law) for this reaction.

CO(g) + Cl2(g) COCl2(g)

Kinetics : RxnOrder (10 Variations)   
(Assessment Material (1))
For the reaction below, determine the order with respect to each reactant and the overall order.
2NO2(g) + F2(g) 2NO2F(g)
rate = k[NO2][F2]
Gases : GasRxnStoich (10 Variations)   
(Assessment Material (1))
One of the reactions in the process of obtaining very pure silicon for the microelectronics industry is shown below. If 24 g of SiO2 is reacted with an excess of carbon, what volume of gaseous carbon monoxide will be produced at a temperature of 17oC and a pressure of 735 mm Hg?

SiO2(s) + 2C(s)Si(S) + 2CO(g)

Equilibrium : InterpretEqConsts (12 Variations)   
(Assessment Material (1))
The following reaction has an equilibrium constant of 1.2x1018 at 25oC.

CH4(g) + Cl2(g) CH3Cl(g) + HCl(g)

Which of the following statements is true?

Equilibrium : EquilExpressions (15 Variations)   
(Assessment Material (1))
What is the correct equilibrium constant expression for the balanced reaction shown below?

C3H8(g) + 5O2(g) 3CO2(g) + 4H2O(l)

Equilibrium : EqConstConcData (4 Variations)   
(Assessment Material (1))
SbCl5(g) SbCl3(g) + Cl2(g)

You have 0.50 mol SbCl5 present initially in a 1.0L flask. The system is allowed to reach equilibrium at 450oC. There is 0.10 mol Cl2 present at equilibrium. What is the equilibrium constant, K?

Equilibrium : CalcMolesAtEquil (15 Variations)   
(Assessment Material (1))
The following reaction has an equilibrium constant of 0.083 at 900oC.

COCl2(g) CO(g) + Cl2(g)

If you have 1.00 mole of COCl2(g) in a 1.00L container initially, how many moles of COCl2 will be present when the system reaches equilibrium?

Electrochemistry : IDRedOxAgents (20 Variations)   
(Assessment Material (1))
In the following balanced reaction, identify the oxidizing and reducing agents.

Fe + Fe2(SO3)3 Arrow 3FeSO3

Electrochemistry : IDHalfRxns (20 Variations)   
(Assessment Material (1))
What are the half-reactions for the reaction of Cs and Cl2 in the formation of CsCl2?

Cs + Cl2 Arrow CsCl2

Electrochemistry : ElectrolysisCalcs (20 Variations)   
(Assessment Material (1))
Calculate the mass of gold that could be plated from a solution with a current of 0.40 A for 22 min.

Au3+(aq) + 3 electrons Arrow Au(s)

Electrochemistry : ECellObservations (20 Variations)   
(Assessment Material (1))

Consider the electrochemical cell diagram shown below. As you observe the reaction in the cell, you notice that the tin electrode seems to be disappearing while there are deposits forming on the silver electrode. Which of the following is a correct statement?

Biochemistry : HBondingDNA (9 Variations)   
(Assessment Material (1))
The structure and replication of DNA are strongly dependent on the hydrogen bonding system present in the double helix. How many functional groups in thymine can participate in hydrogen bonding? (This means all the groups, not just the ones that actually participate in hydrogen bonding in the double helix.)
Atomic_Structure_and_the_Periodic_Table : BohrConceptMap (4 Variations)   
(Assessment Material (1))
In a concept map the terms are connected with arrows. The words along an arrow can be placed between the words in two ovals to make a true statement.

An incomplete concept map is shown below, which set of terms for A, B, C and D would result in a correct map based on the concept of wave mechanics applied to a hydrogen atom?

Acids_and_Bases : ConjugateAcidBase (20 Variations)   
(Assessment Material (1))
Identify the acid and base that are reactants and the conjugate acid and conjugate base that are products in the following equation:
HI(aq) + H2O(l)  H3O+(aq) + I-(aq)
Thermochemistry : EnthalpyEnergy (10 Variations)   
(Assessment Material (1))
2SO2(g) + O2(g)2SO3(g)
Horxn = -197.78 kJ
How much energy is transferred when 96.6 g of SO2 reacts to form SO3?
Equilibrium : RxnDirectAndTemp (16 Variations)   
(Assessment Material (1))
2 SO2(g) + O2(g) 2 SO3(g)
The reaction above has an equilibrium constant of 0.25 at 830oC, and Horxn = -197.78 kJ/mol under standard conditions. Under which conditions will this reaction produce the most sulfur trioxide?
Equilibrium : LeChatPrinciple (18 Variations)   
(Assessment Material (1))
Consider the following equilibrium, established in a 2 L flask at 30oC.

CO(g) + H2O(g) CO2(g) + H2(g) H0= -41.2 kJ

What will happen to the concentration of CO2 if the temperature is increased?

Equilibrium : EqConstRelationships (12 Variations)   
(Assessment Material (1))
The equilibrium constant for the reaction of hydrogen gas and ethene to produce ethane under certain conditions is 9.8 x 1018.
H2(g) + C2H4(g) C2H6(g) K = 9.8 x 1018

What is the equilibrium constant for the following reaction under the same conditions?
C2H6(g) H2(g) + C2H4(g) K = ?

Electrochemistry : BatteryHalfRxns (20 Variations)   
(Assessment Material (1))
The two half-reactions for the LeClanche dry cell battery are shown below. Identify the oxidizing and reducing agents in this cell.

Zn(s) Arrow Zn2+(aq) + 2e-
2NH4+(aq) + 2e- Arrow 2NH3(g) + H2(g)

Acids_and_Bases : MolcScaleAcidBase (10 Variations)   
(Assessment Material (1))
Study the four drawings below and then decide which best represents an aqueous solution that has

(Water molecules are not shown in the diagrams.)

Stoichiometry : DiagramRxnProds (6 Variations)   
(Assessment Material (1))
According to the law of conservation of matter, which of the following diagrams represents possible products of the following reaction?

A2 + 2B2

Reactions : ReactionType (9 Variations)   
(Assessment Material (1))
The reaction Mg + 2HCl MgCl2 + H2 is an example of a(n)
Stoichiometry : BalanceRxn (14 Variations)   
(Assessment Material (1))
The reaction of methane with oxygen has the following unbalanced equation

CH4(g) + O2(g) CO2(g) + H2O(l)

The coefficient for oxygen in the balanced equation is ...

Special_Topics : PolymerType (21 Variations)   
(Assessment Material (1))
Identify the following polymer as a condensation or addition polymer. Is the polymer composed of single type of monomer or is it a copolymer?
Special_Topics : CondAddMonomers (19 Variations)   
(Assessment Material (1))
Which of the following compounds are more likely to be a part of an addition polymer? (Make sure you can see all of all three structures.)
Reactions : MetalActivitySeries (10 Variations)   
(Assessment Material (1))
Predict whether the following reaction will occur in aqueous solution.

Zn(ClO3)2(aq) + Ni(s)

Reactions : BalanceIonEquation (10 Variations)   
(Assessment Material (1))
What is the balanced net ionic equation for the following reaction:

AgNO3(aq) + HCl(aq) AgCl (s) + HNO3(aq)

Organic : Isomers (11 Variations)   
(Assessment Material (1))
Which of the following molecules are isomers?

(Make sure you can see all of all three structures.)

Molecular_Structure : MatchOrganicAngles (10 Variations)   
(Assessment Material (1))
1-amino-2-naphthol-6-sulfonic acid is used as a photographic developer. Its structure is shown below, although lone electron pairs are not shown.


Match the designated bond angles to the appropriate values.

Matter_and_Measurement : ConversionFactor (4 Variations)   
(Assessment Material (1))
Which conversion factor is needed to complete the dimensional analysis for the following problem?

It costs $3 per package of 10 pairs of socks. How much does 2 pairs of socks cost?

Kinetics : CompareEnergyProfile (11 Variations)   
(Assessment Material (1))
Consider the following reactions that take place at the same temperature, begin with the same molar concentrations, and whose energy profiles are presented below:
Atoms,_Molecules_and_Ions : MolcFormulaTypes (8 Variations)   
(Assessment Material (1))

The structural formula for 2-methyl-butane is given below. What is the molecular formula for 2-methyl-butane?

Atomic_Structure_and_the_Periodic_Table : ElectronBoxConfig (10 Variations)   
(Assessment Material (1))
Which of the elements or ions below has the following orbital box diagram?

Atomic_Structure_and_the_Periodic_Table : ParaDiMagnetVideo (8 Variations)   
(Assessment Material (1))

The video shows a substance being slowly moved toward a large magnet. Which of the following ions could be in the compound seen in the video?

Acids_and_Bases : IonizationSteps (20 Variations)   
(Assessment Material (1))
Citric acid (which is a triprotic acid) has the following structure:

Which of the following equations corresponds to the first ionization step of the acid?
Electrochemistry : CalcInterpretEo (20 Variations)   
(Assessment Material (1))
The following electrochemical data may be helpful in answering the question below.

Consider a cell composed of the following half-reactions. Determine the magnitude of E° for the cell and decide whether the reaction will be product-favored or reactant-favored as written.

Cr(s)  Cr3+(aq) + 3e-
Ce4+(aq) + e-  Ce3+(aq)

Thermodynamics : GibbsFromHSandT (5 Variations)   
(Assessment Material (1))
On the space shuttle, the carbon dioxide produced by the astronauts is handled by an environmental control system that utilizes the following reaction.

H° = -138.4 kJ and S° = -139 J/K Calculate G° at 25°C for this reaction.
Thermodynamics : DetermineRxnFavored (8 Variations)   
(Assessment Material (1))
When industrial plants burn coal, sulfur dioxide is produced. Sulfur dioxide is a primary pollutant that contributes to both industrial smog and acid rain. Is this process of producing sulfur dioxide product-favored?

Using

Thermodynamics : CalcMinSpontTemp (9 Variations)   
(Assessment Material (1))
Calculate the minimum temperature above which the following reaction will be product-favored (spontaneous).


Thermodynamics : CalcDeltaS (9 Variations)   
(Assessment Material (1))
Using , calculate the entropy change for the reaction.
Thermodynamics : CalcDeltaG (14 Variations)   
(Assessment Material (1))
Using , calculate the Gibbs free energy change for the following reaction which produces the metal zinc from its ore zinc(II) oxide.
2 ZnO(s) 2 Zn(s) + O2(g)

Thermochemistry : CalcHCombustion (6 Variations)   
(Assessment Material (1))
Using the thermodynamic data given in , determine the enthalpy change for the combustion of ethane to produce carbon dioxide and water vapor.

2C2H6(g) + 7O2(g) 4CO2(g) + 6 H2O(g)

Organic : PredictProductEster (10 Variations)   
(Assessment Material (1))
Which ester will be formed by the following reaction?
Organic : IDChiralAtoms (20 Variations)   
(Assessment Material (1))
Identify the chiral carbon atom(s), if any, in the following structure. The carbon atoms have been numbered for easier identification.


Acids_and_Bases : TitrationCurveKaKb (8 Variations)   
(Assessment Material (1))
Study the graph of the titration of a weak acid with a strong base shown below. What is the approximate Ka for this acid?

Kinetics : InitialRateMethod (16 Variations)   
(Assessment Material (1))
Use the experimental data below to determine the rate equation for the following reaction.


Kinetics : ExpDataRateConst (16 Variations)   
(Assessment Material (1))
Use the experimental data below to determine the rate constant for the following reaction.


Equilibrium : EquilAndRxnRates (8 Variations)   
(Assessment Material (1))

For the reaction of A B, which of the following statements about the rates of forward and reverse reactions is true at time x?

Kinetics : IntegratedRateLaw (6 Variations)   
(Assessment Material (1))
The following kinetics information may be useful in answering this problem.

Use the plots below to determine the order of the reaction with respect to A.



Gases : RadicalGasRxns (17 Variations)   
(Assessment Material (1))
Complete the following reaction. (All reactants and products are gases.)
NO2 + NO3
Biochemistry : NameTripeptide (4 Variations)   
(Assessment Material (1))
What is the name of the tripeptide below?

Thermochemistry : CalcHBondEnergy (14 Variations)   
(Assessment Material (1))
Use the bond energies given in to estimate the Ho for the reaction given below:

hint: both carbon dioxide and molecular oxygen have double bonds

Biochemistry : Disaccharide (20 Variations)   
(Assessment Material (1))
Classify each of the following disaccharides as having an or glycosidic bond.
Thermochemistry : HeatCapacityLiq (4 Variations)   
(Assessment Material (1))
100 g of water (c=4.184 J/g.oC), 100 g of ethanol (c=2.46 J/g.oC), 100 g of carbon tetrachloride (c=0.861 J/g.oC), and 100 g of ethylene glycol (c=2.42 J/g.oC) at 50oC were each placed into a separate coffee cup calorimeter and the temperature recorded. The temperature of the surroundings was 20oC. After one hour the temperature of which substance would have changed by the largest amount? Assume that the rate of heat transfer from the coffee cup to the surroundings was the same in each case.
Thermochemistry : HeatCapacityGraph (6 Variations)   
(Assessment Material (1))

Consider the graph above. Which of these substances has the highest specific heat capacity?

Thermochemistry : GeneralEnergy (10 Variations)   
(Assessment Material (1))
Which of the following statements about energy is NOT true?
Thermochemistry : FuelAmpWattHeat (4 Variations)   
(Assessment Material (1))
Gasoline has an enthalpy of combustion of approximately 24000 kJ/gallon. When gasoline burns in an automobile engine, approximately 30% of the energy released is used to produce mechanical work. The remainder is lost as heat transfer to the engine's cooling system and eventually the atmosphere. As a start on estimating how much heat transfer is required, calculate what mass of water could be heated from 25 to 100oC by the combustion of 1.0 gallon of gasoline in an automobile.
Thermochemistry : CoffeeCupCalorimeter (2 Variations)   
(Assessment Material (1))
A block of copper is heated to {x} °C and then is dropped into a coffee cup calorimeter containing {y} g of water at 25.0 °C. The final temperature of the system is 45.1 °C. What is the mass of the copper block to the nearest gram? (Assume all heat is transferred to the water). Write your answer in the box, and do NOT include units.

Specific heat capacity of copper = 0.383 J/(g*°C)

Specific heat capacity of water = 4.18 J/(g*°C)

Thermochemistry : FlaskTemp (6 Variations)   
(Assessment Material (1))
If 200. J of thermal energy was added to both flasks, which of the following would happen?
Thermochemistry : ConvertEnergyUnits (4 Variations)   
(Assessment Material (1))
The label on a granola bar says it provides 120 Calories. How many kilojoules of energy will this bar provide if it is completely metabolized?
Thermochemistry : CalcHStateChange (4 Variations)   
(Assessment Material (1))
Calculate the enthalpy change when 100. g of ice at 0.0 oC is heated to liquid water at 50.0oC. (The heat of fusion for water is 333 J/g.)
Thermochemistry : BondEnergies (10 Variations)   
(Assessment Material (1))
Use to determine which of the following requires the most energy.
Thermochemistry : BombCalorimeter (4 Variations)   
(Assessment Material (1))
Stearic acid (CH3(CH2)16CO2H) is a fatty acid, the part of fat that stores most of the energy. 1.00 g of stearic acid was burned in a bomb calorimeter. The bomb had a heat capacity of 652 J/oC and a 500. g water reservoir. If the temperature rose from 25.0 to 39.3 oC, how much heat was released when the stearic acid was burned?
Thermochemistry : SystemSurrExoEndo (4 Variations)   
(Assessment Material (1))
Sulfuric acid is added to water in a beaker and the resulting solution is much warmer than either the water or acid was initially.
Identify the following items as being part of the system or the surroundings, and indicate whether the process is exothermic or endothermic.
Stoichiometry : StoicNeeds (10 Variations)   
(Assessment Material (1))
You have a known mass of a compound X and react it to form compound Y. What is the minimum information you need to find the mass of Y produced?
Stoichiometry : RxnNanoPics (4 Variations)   
(Assessment Material (1))
The following diagram shows a compound reacting to form products. Which equation best describes the stoichiometry of the reaction shown in the diagram?

Stoichiometry : PrecipYield (3 Variations)   
(Assessment Material (1))
In a laboratory experiment to determine accurately the amount of barium in solution, aqueous sulfuric acid was added to the solution to precipitate barium sulfate, which was then filtered and weighed. In this experiment it is MOST important that ...
Stoichiometry : NanoPicOfProducts (14 Variations)   
(Assessment Material (1))
The diagram below is representative of a tiny portion of a reaction between ammonia and methane. Which of the diagrams below represents the product mixture?


NH3(g) + CH4(g)HCN(g) + 3H2(g)

Stoichiometry : GramMoleProblem (9 Variations)   
(Assessment Material (1))
Which sample contains the largest number of nitrogen atoms?
Stoichiometry : GeneralMassMole (4 Variations)   
(Assessment Material (1))
10.0 g of nitrogen monoxide is reacted with 10.0 g of oxygen to form nitrogen dioxide. Which of the following statements is true?
Stoichiometry : FormulaFromComp (8 Variations)   
(Assessment Material (1))
Lactic acid is the substance that makes your muscles burn when you've been exercising hard. Lactic acid is composed of 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen by weight. If it has a molar mass of 90 g/mol, what is its molecular formula?
Stoichiometry : ExplainYldError (4 Variations)   
(Assessment Material (1))
Your TA gives you an aqueous solution containing an unknown quantity of AgNO3(aq) and an unknown quantity of Mg(NO3)2(aq). You are asked to determine the molarity of Ag+ in the solution. You add HCl(aq) to your unknown to precipitate the silver as AgCl(s), then filter out the precipitate, dry it, weigh it, and calculate the concentration of silver ion. However, your TA tells you that your calculated value of [Ag+(aq)] is lower than the actual value. Which of the following could account for your answer being too low? There may be more than one correct answer.
Stoichiometry : EmpirFormulaFromRxn (10 Variations)   
(Assessment Material (1))
When one mole of a diatomic gas, Y2(g), reacts with one mole of hydrogen gas, neither gas is left over. What is the empirical formula of the compound formed?
Stoichiometry : CompareParticles (20 Variations)   
(Assessment Material (1))
Which has the greater number of particles, 1 mol O2 or 1 mol O?
Stoichiometry : CombustionAnalysis (10 Variations)   
(Assessment Material (1))
While working in the lab, you find a bottle of white powder labeled "analgesic compound #5". Since the original investigator neglected to record the identity of the substance, you decide to perform a combustion analysis to identify the compound. You have a 65.7 g sample that when burned produces 182 g CO2 and 51.7 g H2O. What is the formula of this compound? (The compound only consists of C,H, and O.)
Stoichiometry : CalcWeightPercent (8 Variations)   
(Assessment Material (1))
What is the weight percent of oxygen in LiHCO3?
Stoichiometry : CalcPercentYield (8 Variations)   
(Assessment Material (1))
When copper is heated in air, copper(II) oxide is formed. In a given experiment, 1.50 g copper was heated to yield 1.76 g copper(II) oxide. What is the percent yield?
Stoichiometry : AtomsAndGrams (10 Variations)   
(Assessment Material (1))
How many moles of atoms does a 500. g bar of gold contain?
Special_Topics : SmogFormation (20 Variations)   
(Assessment Material (1))
In which of the following scenarios is the formation of photochemical smog most likely?
Special_Topics : PlasticRecycling (20 Variations)   
(Assessment Material (1))
Which of the following statements is not one of the reasons usually given in support of recycling plastics?
Special_Topics : OctaneRating (10 Variations)   
(Assessment Material (1))
Which of the following compounds is least helpful in preventing engine knocking in an automobile?
Special_Topics : IDMonomerFromPoly (20 Variations)   
(Assessment Material (1))
Identify the monomer used to produce the following polymer.
Special_Topics : OzoneDepletion (8 Variations)   
(Assessment Material (1))
Use the EPA Web site to answer the following question.

Which of the following ozone depleting compounds would be the least harmful substance to the ozone layer?

Special_Topics : GeneralOzone (17 Variations)   
(Assessment Material (1))
Which of the following statements is not an accurate description of the roles ozone plays in the atmosphere?
Special_Topics : GeneralFuel (6 Variations)   
(Assessment Material (1))
Which of the following statements is not accurate?
Special_Topics : RainFallpH (20 Variations)   
(Assessment Material (1))
The rainfall in central Wisconsin has a pH of 4.8 (National Atmospheric Deposition Program). Take a look at the EPA webpage Effects of Acid Rain: Lakes & Streams. This site has a chart of the pH at which several aquatic species begin to suffer. Determine which of the following species will be most affected by rainfall of this acidity if the lakes and streams in central Wisconsin aren't buffered enough to neutralize some of the acid. (There may be more than one correct answer.)
Special_Topics : GeneralAcidRain (20 Variations)   
(Assessment Material (1))
Which of the following statements about acid rain is the most correct?
Special_Topics : Copolymerization (20 Variations)   
(Assessment Material (1))
Identify the polymer produced from the polymerization of glycolic acid.
Special_Topics : AirPollutants (20 Variations)   
(Assessment Material (1))
Which of the following air pollutants can be described as a photochemically active free radical that contributes to acid rain and respiratory irritation?
Special_Topics : BiopolyFromMonomer (20 Variations)   
(Assessment Material (1))
Match each of the following biomolecules to the type of biopolymer it will form.
Solutions : WtPercentToMolarity (4 Variations)   
(Assessment Material (1))
A common concentration unit used commercially is percent weight per volume (%W/V) which is the number of grams of solute in 100 mL of solution. A bottle of vinegar contains 5 %W/V acetic acid (CH3COOH). What is the molar concentration of acetic acid in the vinegar?
Solutions : SolutionNanoPics (4 Variations)   
(Assessment Material (1))
The drawings below represent flasks of aqueous solutions. Each pink dot represents a dissolved solute particle.
Which of the following solutions is most concentrated?

500 mL
Solution A
500 mL
Solution B
500 mL
Solution C
250 mL
Solution D
250 mL
Solution E
250 mL
Solution F

Solutions : SolnPrepProcedure (10 Variations)   
(Assessment Material (1))
You want to prepare 250mL of a 0.0150M solution of KCl. Which of the following procedures would give you the best results?
Solutions : SolnPrepByMass (4 Variations)   
(Assessment Material (1))
You are required to prepare 5 L of a solution containing 1.000 x 10-3 mol/L of Cu2+(aq). Which of the following procedures would produce an appropriate solution?
Solutions : SolnPrepByDilution (10 Variations)   
(Assessment Material (1))
For the analysis of trace metals it is necessary to prepare solutions of very low concentrations from a stock solution of higher concentration using a micropipet and a volumetric flask. What volume of a 0.0010 M solution of Zn(NO3)2 (aq) would be required to prepare a 5.0 nM solution of Zn2+ in a 250mL flask?
Solutions : SolnConcAfterMixing (4 Variations)   
(Assessment Material (1))
10 mL of 0.1 M BaCl2(aq) is mixed with 10 mL of 0.1 M AgNO3(aq). What are the concentrations of the ions in the final mixture?
Solutions : ReverseOsmosis (20 Variations)   
(Assessment Material (1))
You are given a water sample that contains ammonium chloride (NH4Cl). You determine the concentration of the salt to be 0.500 M and decide to purify the water using reverse osmosis. What is the minimum pressure that must be applied at 30.0oC to force the water through the membrane?
Solutions : RelativeConc (4 Variations)   
(Assessment Material (1))
What are the relative concentrations of the ions in 0.10 M aqueous sulfuric acid?
Solutions : MixturesMolcPics (11 Variations)   
(Assessment Material (1))
Which of the following combinations of substances corresponds to the molecular scale diagram shown below?
Solutions : MassSoluteInSoln (10 Variations)   
(Assessment Material (1))
What is the mass of the solute in 500mL of 0.341M ammonium chloride?
Solutions : IonConcentration (4 Variations)   
(Assessment Material (1))
Which of the following solutions has the greatest concentration of Na+ ions?
Solutions : IDColloidType (20 Variations)   
(Assessment Material (1))
What type of colloid is pigmented plastic?
Solutions : GramsToMolalSoln (20 Variations)   
(Assessment Material (1))
How many grams of citric acid need to be added to 750 ml of ethanol to make a 0.50 m solution?

Density (g/ml)

Molecular Weight (g/mol)

Citric acid

1.665

192.14

Ethanol

0.7893

46.07

Solutions : GeneralSurfactants (20 Variations)   
(Assessment Material (1))
You can make homemade soap by combining a fat (tallow, lard, vegetable oil, etc.) with a source of alkali (lye). What is the purpose of the fat in soap?
Solutions : GeneralSolutions (10 Variations)   
(Assessment Material (1))
You have 500.0mL of 0.100M aqueous MgBr2. Which of the following statements are true?
Solutions : FreezePtDepression (20 Variations)   
(Assessment Material (1))
It takes 6.86 kg of ethylene glycol (antifreeze) to decrease the freezing point of 6.50 kg of water to -25.0oF (-31.7oC). How much sodium chloride (NaCl) would it take to decrease the freezing point of 6.50 kg of water to -25.0oF? (Assuming all the salt will dissolve in that amount of water.)
Solutions : ConvertConcUnits (10 Variations)   
(Assessment Material (1))
The maximum concentration of arsenic in drinking water that is allowed by the EPA is 0.050 mg/L. Express this as a weight percent. (You can assume the density of the water solution is 1.0g/mL.)
Reactions : WillSolnConduct (5 Variations)   
(Assessment Material (1))
One gram of each of the following compounds is mixed with 100mL of water. Which will form solutions that will conduct electricity?
Reactions : StrongWeakAcidBase (10 Variations)   
(Assessment Material (1))
Which of the following are strong acids?
Reactions : Solubility (8 Variations)   
(Assessment Material (1))
Which of the following compounds are soluble in water?
Reactions : PredictRxnProducts (5 Variations)   
(Assessment Material (1))
What are the most likely products from the reaction of aqueous sulfuric acid and aqueous sodium hydroxide?
Reactions : PredictProducts (10 Variations)   
(Assessment Material (1))
Predict the product(s) of the following displacement reaction.

TiCl4 + 2Mg

Reactions : NotRedoxRxn (4 Variations)   
(Assessment Material (1))
Which of the following is a NOT a redox reaction?
Reactions : NanoPicOfProducts (14 Variations)   
(Assessment Material (1))
The diagram below is representative of a tiny portion of a reaction between ammonia and methane. Which of the diagrams below represents the product mixture?


NH3(g) + CH4(g)HCN(g) + 3H2(g)

Reactions : IDOxidationNumber (10 Variations)   
(Assessment Material (1))
What is the oxidation number of sulfur in barium sulfate (BaSO4)?
Reactions : HighOxNumber (10 Variations)   
(Assessment Material (1))
In which of the following does sulfur have the highest oxidation number?
Reactions : GeneralChemRxn (4 Variations)   
(Assessment Material (1))
In a balanced chemical equation

Check all that apply.

Reactions : ExchangeRxn (10 Variations)   
(Assessment Material (1))
Which of the following compounds would result in an exchange reaction if mixed in an aqueous solution with Ba(OH)2?
Reactions : AcidBaseRxns (20 Variations)   
(Assessment Material (1))
In order to answer the following questions, write the net ionic equation for the reaction between equal volumes of 0.10 M solutions of the following acid and base:

KOH(aq) + HBr(aq)

What are the reaction products? Does the reaction yield an acidic, basic, or neutral aqueous solution?

Reactions : RedoxAgents (10 Variations)   
(Assessment Material (1))
Identify each of the following as a reducing agent or an oxidizing agent.
Reactions : GeneralRxnType (10 Variations)   
(Assessment Material (1))
Identify each of the following statements as describing a combination, displacement, decomposition, or exchange reaction.
Organic : HsOnAlkaneBackbone (10 Variations)   
(Assessment Material (1))

The carbon skeleton for 2-methylbutane is shown below. How many hydrogens are present?

Organic : FunctionalGroups (18 Variations)   
(Assessment Material (1))
The structure for niacin (one of the B-vitamins) is shown below. Which of the following functional groups is present in niacin?
Organic : FindIdenticalIsomers (20 Variations)   
(Assessment Material (1))
Which of the following structural isomers for C6H14 are actually the same structure?
Organic : CisTransPossible (20 Variations)   
(Assessment Material (1))
Which of the following molecules can have cis and trans isomers? (You may select more than one.)
Organic : AlkaneNomenclature (10 Variations)   
(Assessment Material (1))
What is the correct name for the following compound:
CH3CH2CH2CH3
Organic : AlkaneIsomers (8 Variations)   
(Assessment Material (1))
Pentane has several isomers. Which of the following condensed formulas is NOT an isomer of pentane?
Organic : AlcoholOxidation (10 Variations)   
(Assessment Material (1))
Which of the following alcohols will be oxidized by potassium permanganate to form a ketone?
Organic : AlcoholClassification (10 Variations)   
(Assessment Material (1))
Match the following alcohols to the proper classification. (You may not need to use all of the classifications.)
Molecular_Structure : IDNonpolarMolc (10 Variations)   
(Assessment Material (1))
Which of the following molecules is nonpolar?
Molecular_Structure : Hybridization (10 Variations)   
(Assessment Material (1))
Which of the following molecules/ions have sp hybridization around the indicated atom?
Molecular_Structure : ElectronPairGeometry (20 Variations)   
(Assessment Material (1))
Which of the molecules/ions below have a linear electron-pair geometry?
Molecular_Structure : BondAngle (6 Variations)   
(Assessment Material (1))
Which of the following has the smallest H-X-H bond angle?
Molecular_Structure : AtomFromGeometry (8 Variations)   
(Assessment Material (1))
Which atom or atoms could be the central atom, X, in the stable molecule XH3 with one lone pair of electrons?
Molecular_Structure : MolecularGeometry (23 Variations)   
(Assessment Material (1))
Which of the following molecules/ions have a linear molecular geometry like the structure shown below?

Be patient. It may take a while for the structure to load.


Matter_and_Measurement : UseDensity (10 Variations)   
(Assessment Material (1))
If a 10.0 inch aluminum skillet weighs 3 pounds, how many cm3 of aluminum does it contain? The density of aluminum is 2.70 g/cm3.
Matter_and_Measurement : QualQuantObserv (10 Variations)   
(Assessment Material (1))
Which of the following statements are quantitative observations about carbon?
Matter_and_Measurement : PhysOrChemChange (10 Variations)   
(Assessment Material (1))
Which of the following are physical changes?
Matter_and_Measurement : PhaseProperties (10 Variations)   
(Assessment Material (1))
Does the following statement apply to solids, liquids, or gases?
It has a fixed volume.
Matter_and_Measurement : NumOfSigFigs (4 Variations)   
(Assessment Material (1))
How many significant figures will the answer to the following problem contain?
Matter_and_Measurement : NanoScalePhases (8 Variations)   
(Assessment Material (1))
Which of the following contains the most active particles?
Matter_and_Measurement : ElementType (10 Variations)   
(Assessment Material (1))
Which of the following are metals?
Matter_and_Measurement : ConvertUnits (10 Variations)   
(Assessment Material (1))
Your textbook is approximately 8.75 inches by 10.25 inches. What are these measurements in centimeters?
Matter_and_Measurement : CompareFCTemps (10 Variations)   
(Assessment Material (1))
Which is the higher temperature, 350oC or 350oF?
Matter_and_Measurement : ClassifyMatter (8 Variations)   
(Assessment Material (1))
Which of the following descriptions best classifies aluminum foil?
Matter_and_Measurement : CalcDensity (5 Variations)   
(Assessment Material (1))
What is the density of a 7000 gram brick that is 4 inches x 5 inches x 3 inches?
Matter_and_Measurement : ThryOrHypothesis (6 Variations)   
(Assessment Material (1))
Identify each of the following statements as a theory or a hypothesis.
Matter_and_Measurement : HomoOrHeteroMix (10 Variations)   
(Assessment Material (1))
Identify the following as homogeneous or heterogeneous mixtures.
Matter_and_Measurement : ElementState (10 Variations)   
(Assessment Material (1))
Identify how each of the following elements exist under normal conditions.
Matter_and_Measurement : ElemCompdMix (10 Variations)   
(Assessment Material (1))
Classify each of the following as an element, compound, or mixture.
Kinetics : RxnMechanisms (14 Variations)   
(Assessment Material (1))
Experiments show that the reaction of nitrogen dioxide and carbon monoxide
NO2 + CO NO + CO2

has the following rate expression at high temperatures:

Rate=k[NO2][CO]

Is the following mechanism compatible with the experimental information?
(1) NO2 + CO O-N-O-C-O (slow)
(2) O-N-O-C-O NO + CO2 (fast)
Choose the best answer.

Kinetics : RateLawChangeConc (10 Variations)   
(Assessment Material (1))
The rate law for a reaction is rate=k[A][B]. If the concentration of A doubles, the rate of the reaction will do which of the following?
Kinetics : IntermediateInMech (15 Variations)   
(Assessment Material (1))
Suppose that for the reaction of nitrogen dioxide and carbon monoxide
NO2 + CO NO + CO2

the following mechanism has been proposed at high temperatures:
(1) NO2 + CO O-N-O-C-O (slow)
(2) O-N-O-C-O NO + CO2 (fast)
Check the box for each species that is an intermediate in this mechanism.

Kinetics : ElementaryRxnOrNot (9 Variations)   
(Assessment Material (1))
Which of the following reactions could be elementary and unimolecular reactions?
Kinetics : CatalyticConverters (4 Variations)   
(Assessment Material (1))
The following table illustrates the changes in emissions requirements for automobiles:
Pollutant1970 Emissions1990 EmissionsCA ultra-low emissions
CxHy1.5 g/mile0.25 g/mile0.04 g/mile
CO15 g/mile3.4 g/mile1.7 g/mile
NOx3.1 g/mile0.4 g/mile0.2 g/mile
Catalytic converters are used in automobiles to convert pollutants in engine emissions to benign products. Catalytic converters in today's automobiles are made of a porous ceramic brick that has been coated with catalysts, additives, stabilizers, and support materials. Corning has developed bricks that have very thin-walled channels with 600 channels per square inch. Which of the following research goals did they target?
Kinetics : CatalystTrueFalse (7 Variations)   
(Assessment Material (1))
Check the box for each statement about catalysts that is true.
Kinetics : ArrheniusTemp (3 Variations)   
(Assessment Material (1))
The activation energy for the isomerization of cyclopropane to propene is 274 kJ/mol. By what factor does the rate of reaction increase as the temperature rises from 500oC to 550oC assuming all else remains constant? (R = 8.314 J/mol k)

Hint: This is asking for the ratio of rates which is proportional to the ratio of the rate constants, all else being equal.

Kinetics : ArrheniusRateConst (4 Variations)   
(Assessment Material (1))
CH3CH2NO2 C2H2 + HNO2

Using the graph below, calculate the rate constant for this reaction at 40.0oC.

Kinetics : ArrheniusActEnergy (4 Variations)   
(Assessment Material (1))
The rate constant for the first-order dehydration of tert-butyl alcohol at 500oC is 1.20 x 10 -4 s -1. The rate constant for this process at 600oC is 6.80 x 10 -3 s -1. Calculate the activation energy for this reaction in kJ/mol. (R = 8.314 J/mol K)
Kinetics : RateConstantUnits (8 Variations)   
(Assessment Material (1))
The isomerization of CH3NC to CH3CN has a rate constant of 0.46 s-1 at 600 K.

(1) Based on the units of the rate constant, what is the order of the reaction? {1:MULTICHOICE:zero-order#No, that is not correct.~=first-order#Correct!~second-order#No, that is not correct.~third-order#No, that is not correct.}

(2) What is the concentration of CH3CN after 0.20 minutes of reaction if the initial concentration is 0.10 M? {1:NUMERICAL:=4e-4:1e-5#Correct!~%50%4e-4:5e-5#Close, but not quite.}(Do not include units!)

Kinetics : InterpretEnergyProfile (16 Variations)   
(Assessment Material (1))
Use the energy profile below to decide if the following statements are true or false.
Kinetics : Enzyme (7 Variations)   
(Assessment Material (1))
Trypsin assists in digestion by breaking proteins down into smaller peptides. However, this process is not as efficient in the presence of fluorophosphates. Identify the role of each of these components.
Kinetics : ConcVsTimeGraph (8 Variations)   
(Assessment Material (1))
The following graph shows the change in concentration as a function of time for the reaction:
2NO2(g) + F2(g) 2NO2F(g)
What do each of the curves A, B, and C represent?
Gases : VolGasReactInTorch (10 Variations)   
(Assessment Material (1))
Oxyacetylene torches used in high-temperature welding use a combination of oxygen and acetylene. The combustion of acetylene (C2H2) occurs in these torches. What volume of oxygen is needed to react with 250 mL of acetylene?
Gases : RealGases (6 Variations)   
(Assessment Material (1))
Which gas in the following list will have the greatest deviation from ideal behavior at STP?
Gases : OzoneMolcsFromppm (10 Variations)   
(Assessment Material (1))
Although ozone is an important component of the upper atmosphere, long-term exposure to ozone in the air we breathe can cause inflammation of the lung, impairment of lung defense mechanisms, and irreversible changes in lung structure. The EPA has set an 8 hour limit for ozone of 0.08 ppm as an air quality standard for cities. At the EPA limit, how many ozone molecules are present in 5.0 liters of air at 25oC and 0.967 atm? (Hint: assume that air is an ideal gas and calculate the total number of molecules there are in 5.0 L. Then use the definition of ppm.)
Gases : KineticMolcThry (7 Variations)   
(Assessment Material (1))
Which postulate of kinetic-molecular theory best accounts for the fact that gases can be compressed easily?
Gases : IDGasFromVelocity (8 Variations)   
(Assessment Material (1))
The following are graphs of molecular velocities versus the relative number of molecules for argon, chlorine, methane and xenon at 300K. Which graph is for argon?
Gases : IdealGasMolarMass (10 Variations)   
(Assessment Material (1))
A sealed flask contains 3.1 L of a gas at 2.4 atm and 22.7oC. If the density of the gas is 9.7 g/L, what is its molar mass? (You can assume that the gas behaves ideally.)
Gases : GasLaws (2 Variations)   
(Assessment Material (1))
Note: This is a calculation type question. If you exit the quiz without submitting it and you do not save an answer before exiting the quiz, the values in the question may change when you enter the quiz again.

You purchase a propane tank that can hold gas safely up to a pressure of {x} atm. When the tank contains 100. grams of propane at {y}°C, the gas exerts a pressure of {z}atm. What is the highest temperature to which the propane can be heated safely? (Report your answer in Kelvins.)

Gases : IdealGasLaw (11 Variations)   
(Assessment Material (1))
What volume is occupied by 2.60 moles of nitrogen at 1.70 atm and 14.9oC?
Gases : GasRxnVolumes (10 Variations)   
(Assessment Material (1))
A gas phase reaction takes place in a syringe at a constant temperature and pressure. If the initial volume before reaction is 30 mL and the final volume after the reaction is complete is 15 mL, which of the following reactions took place? (Note: You can assume that you start with stoichiometric amounts of the reactants, the reaction goes to completion and that the gases behave ideally.)
Gases : GasProperties (9 Variations)   
(Assessment Material (1))
Which of the following is NOT a property of gases?
Gases : GasMoleMixPressure (5 Variations)   
(Assessment Material (1))
What is the pressure exerted by a mixture of gases in a 40.0 L container at 127oC if the mixture contains 0.100 mol O2, 0.400 mol CH4, and 0.500 mol SO2?
Gases : GasGramMixPressure (5 Variations)   
(Assessment Material (1))
4.80 g of CH4 is mixed with 17.6 g of CO2 in a 9.00 L flask at a temperature of 67.2oC. What is the total pressure of the flask? (Assume there is no reaction.)
Equilibrium : KspSaturation (12 Variations)   
(Assessment Material (1))
Zn(OH)2 has a Ksp of 4.5 x 10-17. If you have a solution of Zn(OH)2 that has a hydroxide ion concentration equal to 4.6 x 10-6 mol/L, the solution is ... (Assume that the only relevant reaction is the solubility-product equilibrium.)
Equilibrium : KspExpressions (10 Variations)   
(Assessment Material (1))
What is the solubility product expression for Ag3PO4?
Equilibrium : InterpretKsp (16 Variations)   
(Assessment Material (1))
Which of the following salts would give you the highest concentration of phosphate ions in solution if you placed 1 mole of the salt in a liter of water?
Equilibrium : EquilTrueFalse (4 Variations)   
(Assessment Material (1))
Which of the following statements is a true statement concerning a reaction that has reached a state of equilibrium?
Equilibrium : ConcFromKsp (8 Variations)   
(Assessment Material (1))
The Ksp of BaF2 is 1.7 x 10-6 mol/L in water at 25oC. What is the concentration of barium ions in equilibrium with solid barium fluoride? (Assume that the only relevant reaction is the solubility-product equilibrium.)
Equilibrium : CommonIonEffect (9 Variations)   
(Assessment Material (1))
The molar solubility of lead(II) fluoride (PbF2) is 2.1 x 10-3 mol/L in pure water at 25oC. What is the molar solubility of lead(II) fluoride in 0.10 M NaF at 25oC? (Assume that the only relevant reaction is the solubility-product equilibrium.)
Electrochemistry : SacrificialAnode (10 Variations)   
(Assessment Material (1))
The following electrochemical data may be helpful in answering the question below.

One method for protecting metals against corrosion is to connect the metal directly to a "sacrificial anode". This is the method used to protect pipelines and ships hulls. Which of the following metals would you consider the best candidate for a sacrificial anode for a ship's hull? The hull is steel (which is mostly iron).

Electrochemistry : GeneralElectrochem (20 Variations)   
(Assessment Material (1))
Which of the following statements is not correct?
Electrochemistry : GeneralCorrosion (10 Variations)   
(Assessment Material (1))
Which of the following statements not is true?
Electrochemistry : ElectrolysisHalfRxns (20 Variations)   
(Assessment Material (1))
The following electrochemical data may be helpful in answering the question below.

What will be the products of the electrolysis of an aqueous solution of Tin (II) sulfate (SnSO4)? (The electrodes themselves are platinum.)

Electrochemistry : CalcStandRedPotential (20 Variations)   
(Assessment Material (1))
The following electrochemical data may be helpful in answering the question below.

Calculate Eo for the following balanced reaction.

Fe(s) + Fe2(SO3)3(s) Arrow 3FeSO3(s)

Electrochemistry : CalcDeltaGfromE (20 Variations)   
(Assessment Material (1))
The following electrochemical data may be helpful in answering the question below.

Calculate the dGo for the oxidation of 2 mole of silver in the following balanced reaction.

2Ag(s) + CaI2(aq) a Ca(s) + 2AgI(s)

Characteristics of Materials   
(Activity, Instructional Material (7), Test, Assessment Material (15))
What makes diapers absorbent? Is peanut butter stickier than syrup or jelly? Strong, stretchy, sticky, or sweet—everything around us has special properties which make them unique. See if you can identify and compare the characteristics of materials.
Chemical & Physical Change   
(Activity, Instructional Material (4), Test, Assessment Material (5))
Everything you see and touch has the ability to change. Sometimes substances change to form new substances. This is called a chemical change. Other times substances change but keep the same identity. This is called a physical change. Try these activities to learn more about chemical and physical change.
Alpha Beta Unsaturated Ketones and Aldehydes (13 Variations)   
()
A collection of 13 assessment questions about Alpha Beta Unsaturated Ketones and Aldehydes
Epoxides (5 Variations)   
()
A collection of 5 assessment questions about Epoxides
Nitriles (1 Variations)   
()
A collection of 1 assessment questions about Nitriles
Sulfur Chemistry (3 Variations)   
()
A collection of 3 assessment questions about Sulfur Chemistry
Substitution and Elimination (6 Variations)   
()
A collection of 6 assessment questions about Substitution and Elimination
Radicals (9 Variations)   
()
A collection of 9 assessment questions about Radicals
Phenols and Aryl Halides (9 Variations)   
()
A collection of 9 assessment questions about Phenols and Aryl Halides
Organometallic (13 Variations)   
()
A collection of 13 assessment questions about Organometallic
Nucleophilic Substitution (18 Variations)   
()
A collection of 18 assessment questions about Nucleophilic Substitution
Nomenclature (10 Variations)   
()
A collection of 10 assessment questions about Nomenclature
NMR (19 Variations)   
()
A collection of 19 assessment questions about NMR
Lipids (2 Variations)   
()
A collection of 2 assessment questions about Lipids
IR (6 Variations)   
()
A collection of 6 assessment questions about IR
Functional Groups (9 Variations)   
()
A collection of 9 assessment questions about Functional Groups
Electrophilic Substitution (3 Variations)   
()
A collection of 3 assessment questions about Electrophilic Substitution
Covalent Bonding (11 Variations)   
()
A collection of 11 assessment questions about Covalent Bonding
Conjugation (1 Variations)   
()
A collection of 1 assessment questions about Conjugation
Anhydrides (2 Variations)   
()
A collection of 2 assessment questions about Anhydrides
Amides (1 Variations)   
()
A collection of 1 assessment questions about Amides
Acyl Chlorides (5 Variations)   
()
A collection of 5 assessment questions about Acyl Chlorides
Carboxylic Acids (14 Variations)   
()
A collection of 14 assessment questions about Carboxylic Acids
Carbohydrates (17 Variations)   
()
A collection of 17 assessment questions about Carbohydrates
Oxidation Reduction Reactions (2 Variations)   
()
A collection of 2 assessment questions about Oxidation Reduction Reactions
Nomenclature (1 Variations)   
()
A collection of 1 assessment questions about Nomenclature
Enamines (6 Variations)   
()
A collection of 6 assessment questions about Enamines
Stereochemistry (21 Variations)   
()
A collection of 21 assessment questions about Stereochemistry
Oxidation Reduction (21 Variations)   
()
A collection of 21 assessment questions about Oxidation Reduction
Esters (8 Variations)   
()
A collection of 8 assessment questions about Esters
Bonding (34 Variations)   
()
A collection of 34 assessment questions about Bonding
Aromatic (26 Variations)   
()
A collection of 26 assessment questions about Aromatic
Amines (30 Variations)   
()
A collection of 30 assessment questions about Amines
Amino Acids (10 Variations)   
()
A collection of 10 assessment questions about Amino Acids
Alkenes and Alkynes (31 Variations)   
()
A collection of 31 assessment questions about Alkenes and Alkynes
Alkenes (16 Variations)   
()
A collection of 16 assessment questions about Alkenes
Alkanes (22 Variations)   
()
A collection of 22 assessment questions about Alkanes
MO Theory (11 Variations)   
()
A collection of 11 assessment questions about MO Theory
Wittig Reactions (4 Variations)   
()
A collection of 4 assessment questions about Wittig Reactions
Synthesis (11 Variations)   
()
A collection of 11 assessment questions about Synthesis
Imines (8 Variations)   
()
A collection of 8 assessment questions about Imines
Beta Dicarbonyl Compounds (13 Variations)   
()
A collection of 13 assessment questions about Beta Dicarbonyl Compounds
Alkylation (6 Variations)   
()
A collection of 6 assessment questions about Alkylation
Aldol Reactions (30 Variations)   
()
A collection of 30 assessment questions about Aldol Reactions
Acetals (9 Variations)   
()
A collection of 9 assessment questions about Acetals
Aldehyde and Ketone Addition (2 Variations)   
()
A collection of 2 assessment questions about Aldehyde and Ketone Addition
Alcohols and Ethers (22 Variations)   
()
A collection of 22 assessment questions about Alcohols and Ethers
Acid Base (44 Variations)   
()
A collection of 44 assessment questions about Acid Base