TIGER

Assessment Questions: 45 results
Solutions : FreezePtDepression (20 Variations)
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 / Solvents
Solutions : GeneralSolutions (10 Variations)
You have 500.0mL of 0.100M aqueous MgBr2. Which of the following statements are true?
Solutions / Solvents
Solutions : SolnPrepProcedure (10 Variations)
You want to prepare 250mL of a 0.0150M solution of KCl. Which of the following procedures would give you the best results?
Solutions / Solvents
Solutions : SolutionNanoPics (4 Variations)
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 / Solvents
Solutions : IonConcentration (4 Variations)
Which of the following solutions has the greatest concentration of Na+ ions?
Solutions / Solvents |
Chemometrics
Solutions : MassSoluteInSoln (10 Variations)
What is the mass of the solute in 500mL of 0.341M ammonium chloride?
Solutions / Solvents |
Chemometrics
Solutions : RelativeConc (4 Variations)
What are the relative concentrations of the ions in 0.10 M aqueous sulfuric acid?
Solutions / Solvents |
Stoichiometry
Solutions : ReverseOsmosis (20 Variations)
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 / Solvents |
Transport Properties
Solutions : SolnConcAfterMixing (4 Variations)
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 / Solvents |
Chemometrics
Solutions : SolnPrepByDilution (10 Variations)
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 / Solvents |
Chemometrics
Solutions : SolnPrepByMass (4 Variations)
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 / Solvents |
Chemometrics
Solutions : ConvertConcUnits (10 Variations)
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.)
Solutions / Solvents |
Nomenclature / Units / Symbols |
Chemometrics
Solutions : GramsToMolalSoln (20 Variations)
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 / Solvents |
Nomenclature / Units / Symbols |
Chemometrics
Solutions : MixturesMolcPics (11 Variations)
Which of the following combinations of substances corresponds to the molecular scale diagram shown below?

Solutions / Solvents |
Noncovalent Interactions |
Precipitation / Solubility
Solutions : WtPercentToMolarity (4 Variations)
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 / Solvents |
Nomenclature / Units / Symbols |
Chemometrics
Solutions : CalcMolarityFromPPT (10 Variations)
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)

Solutions / Solvents |
Nomenclature / Units / Symbols |
Chemometrics
Equilibrium : EquilTrueFalse (4 Variations)
Which of the following statements is a true statement concerning a reaction that has reached a state of equilibrium?
Equilibrium
Equilibrium : KspExpressions (10 Variations)
What is the solubility product expression for Ag3PO4?
Equilibrium
Equilibrium : KspSaturation (12 Variations)
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
Equilibrium : LeChatPrinciple (18 Variations)
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
Equilibrium : RxnDirectAndTemp (16 Variations)
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
Equilibrium : EquilExpressions (15 Variations)
What is the correct equilibrium constant expression for the balanced reaction shown below?

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


Equilibrium
Equilibrium : InterpretEqConsts (12 Variations)
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
Equilibrium : ICETables (16 Variations)
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
Equilibrium : SolubilityPressTemp (16 Variations)
How does increasing the temperature change the solubility of nitrogen in water?
Equilibrium
Equilibrium : CommonIonEffect (9 Variations)
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.)
Equilibrium |
Chemometrics
Equilibrium : ConcFromKsp (8 Variations)
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 |
Chemometrics
Equilibrium : InterpretKsp (16 Variations)
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 |
Chemometrics
Equilibrium : EquilAndRxnRates (8 Variations)

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

Equilibrium |
Kinetics
Equilibrium : EqConstRelationships (12 Variations)
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 = ?


Equilibrium |
Chemometrics
Equilibrium : CalcMolesAtEquil (15 Variations)
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?


Equilibrium |
Chemometrics
Equilibrium : EqConstConcData (4 Variations)
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 |
Chemometrics
Equilibrium : CalcRxnQuotient (13 Variations)
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!}


Equilibrium |
Chemometrics
Equilibrium : CalcKp (2 Variations)
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 |
Chemometrics
Equilibrium : CalcKc (4 Variations)
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 |
Chemometrics
Equilibrium : ConvertKcKp (6 Variations)
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 |
Chemometrics
Equilibrium : MoreMolesAtEquil (19 Variations)
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 |
Chemometrics
Acids_and_Bases : PercentDissociationKa (3 Variations)
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 / Bases |
Reactions |
Aqueous Solution Chemistry |
Equilibrium
Acids_and_Bases : WeakAcidSolnpH (20 Variations)
Given an aqueous solution of 0.30 M acetic acid (Ka = 1.8 x 10-5), the pH is approximately ...
Acids / Bases |
Reactions |
Aqueous Solution Chemistry |
pH |
Equilibrium
Acids_and_Bases : BufferingCapacity (20 Variations)
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 / Bases |
Reactions |
Aqueous Solution Chemistry |
pH |
Equilibrium
Acids_and_Bases : pHDilution (6 Variations)
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 / Bases |
Reactions |
Aqueous Solution Chemistry |
pH |
Equilibrium
Acids_and_Bases : pHBufferCalc (4 Variations)
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 / Bases |
Reactions |
Aqueous Solution Chemistry |
pH |
Equilibrium
Acids_and_Bases : BufferWeakStrong (7 Variations)
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 / Bases |
Reactions |
Aqueous Solution Chemistry |
pH |
Equilibrium
Acids_and_Bases : CalcSolnpH (5 Variations)
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 / Bases |
Reactions |
Aqueous Solution Chemistry |
pH |
Equilibrium
Acids_and_Bases : BufferWeakWeak (14 Variations)
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 / Bases |
Reactions |
Aqueous Solution Chemistry |
pH |
Equilibrium