TIGER

Assessment Questions: 39 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 : 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
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
Kinetics : CompareEnergyProfile (11 Variations)
Consider the following reactions that take place at the same temperature, begin with the same molar concentrations, and whose energy profiles are presented below:
Kinetics
Kinetics : ConcVsTimeGraph (8 Variations)
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?

Kinetics
Kinetics : FactorsAffectingRate (7 Variations)
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
Kinetics : RxnProfileEaDeltaE (11 Variations)
Based on the reaction profile, what is the energy change for the reaction?

Kinetics
Organic : CisTransPossible (20 Variations)
Which of the following molecules can have cis and trans isomers? (You may select more than one.)
Alkenes |
Stereochemistry
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
Kinetics : Enzyme (7 Variations)
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.
Enzymes |
Kinetics
Kinetics : ArrheniusActEnergy (4 Variations)
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 |
Chemometrics
Kinetics : ArrheniusRateConst (4 Variations)
CH3CH2NO2 C2H2 + HNO2

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

Kinetics |
Chemometrics
Kinetics : ArrheniusTemp (3 Variations)
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 |
Chemometrics
Kinetics : CatalystTrueFalse (7 Variations)
Check the box for each statement about catalysts that is true.
Kinetics |
Catalysis
Kinetics : CatalyticConverters (4 Variations)
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 |
Catalysis
Kinetics : ExpDataRateConst (16 Variations)
Use the experimental data below to determine the rate constant for the following reaction.



Kinetics |
Chemometrics
Kinetics : InterpretEnergyProfile (16 Variations)
Use the energy profile below to decide if the following statements are true or false.

Kinetics |
Mechanisms of Reactions
Kinetics : RxnOrder (10 Variations)
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]

Kinetics |
Rate Law
Kinetics : RateConstantUnits (8 Variations)
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 |
Rate Law
Kinetics : ElementaryRxnOrNot (9 Variations)
Which of the following reactions could be elementary and unimolecular reactions?
Kinetics |
Mechanisms of Reactions
Kinetics : InitialRateMethod (16 Variations)
Use the experimental data below to determine the rate equation for the following reaction.



Kinetics |
Chemometrics |
Rate Law
Kinetics : IntegratedRateLaw (6 Variations)
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.




Kinetics |
Rate Law
Kinetics : IntermediateInMech (15 Variations)
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 |
Mechanisms of Reactions
Kinetics : RateLawChangeConc (10 Variations)
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 |
Rate Law
Kinetics : ElementRxnRateLaws (13 Variations)
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 |
Mechanisms of Reactions |
Rate Law
Kinetics : RxnMechanisms (14 Variations)
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 |
Mechanisms of Reactions |
Rate Law