Q: Which of the following is the correct rate law for a reaction that is first order in $$H_2$$ and second order in $$NO$$?

$$\text{Rate} = k[NO]^2[H_2$]$$

Q: Which of the following is a plausible value for the rate of disappearance of $$A$$ from 40 to 60 s, given the trend in the data?

$$7.0 \times 10$$^{-3}$$\ \mathrm{M/s}$$

Question 1

Which of the following factors will NOT increase the rate of a chemical reaction?

Accepted Answer

Decreasing the concentration of reactants

Question 2

For the reaction $$A \rightarrow B$$, the concentration of $$A$$ decreases from 1.00 M to 0.54 M in 20 seconds. What is the average rate of disappearance of $$A$$ during this time interval?

Accepted Answer

$$0.023\ \mathrm{M/s} ($$expressed as a positive value)

Question 3

Given the reaction $$2\ NO(g) + Cl_2$(g) \rightarrow 2\ NOCl(g)$$, if the partial pressure of $$NO is $$decreasing at a rate of $$56\ \mathrm{torr/min}$$, what is the rate of change of the total pressure in the vessel?

Accepted Answer

Increasing at a rate of $$28\ \mathrm{torr/min}$$

Question 4

Which of the following is the correct rate law for a reaction that is first order in $$H_2$$ and second order in $$NO$$?

Accepted Answer

$$	ext{Rate} = k[NO]^2[H_2$]$$

Question 5

If the rate law for a reaction is $$	ext{Rate} = k[A]^2[B]$$, what are the units of the rate constant $$k$$?

Accepted Answer

$$\mathrm{M}^{-1}\mathrm{s}^{-1}$$

Question 6

A reaction is monitored using Beer’s Law, $$A = \varepsilon bc. If $$the path length and extinction coefficient are constant, what happens to the absorbance if the concentration doubles?

Accepted Answer

Absorbance doubles

Question 7

Which plot would yield a straight line for a first-order reaction?

Accepted Answer

$$\ln[A] vs. $$time

Question 8

For a zero-order reaction, which of the following integrated rate laws is correct?

Accepted Answer

$$[A]_t = [A]_0 - kt$$

Question 9

A reaction is found to be second order in $$NO_2. $$Which plot would be linear?

Accepted Answer

$$1/[NO_2$] vs. $$time

Question 10

If a catalyst is added to a reaction, which of the following statements is true?

Accepted Answer

The catalyst increases the rate constant $$k by $$lowering the activation energy

Question 11

Given the following data for the reaction $$2\ $$ClO_2$$(aq) + 2\ OH^-(aq) \rightarrow $$ClO_3$$^-(aq) + $$ClO_2$$^-(aq) + H_2O(l)$$, if the initial rate triples when $$[OH^-] is $$tripled (with $$[$$ClO_2$$]$$ constant), what is the order with respect to $$OH^-$$?

Accepted Answer

First order

Question 12

For the reaction $$A \rightarrow B$$, the concentration of $$B$$ increases from 0.46 M to 0.70 M between 20 s and 40 s. What is the average rate of appearance of $$B$$ during this interval?

Accepted Answer

$$0.012\ \mathrm{M/s}$$

Question 13

Which of the following best describes the units of a rate constant for a first-order reaction?

Accepted Answer

$$\mathrm{s}^{-1}$$

Question 14

A reaction is monitored in a 1 L flask. At $$t=0 s$$, $$[A]=1.00 M $$and $$[B]=0.00 M. At$$ $$t=20 s$$, $$[A]=0.54 M $$and $$[B]=0.46 M. At$$ $$t=40 s$$, $$[A]=0.30 M $$and $$[B]=0.70 M. $$What is the average rate of disappearance of $$A$$ from 20 s to 40 s?

Accepted Answer

$$0.024\ \mathrm{M/s}$$

Question 15

Which of the following is a plausible value for the rate of disappearance of $$A$$ from 40 to 60 s, given the trend in the data?

Accepted Answer

$$7.0 	imes 10$$^{-3}$$\ \mathrm{M/s}$$

Question 16

Which of the following statements about reaction order is correct?

Accepted Answer

The reaction order is determined experimentally.

Question 17

If the rate law for a reaction is $$	ext{Rate} = k[A][B]$$, and $$[A] is $$doubled while $$[B] is $$kept constant, by what factor does the rate increase?

Accepted Answer

It doubles

Question 18

Which of the following best describes a zero-order reaction?

Accepted Answer

The rate is independent of the concentration of reactant

Question 19

A student observes that the plot of $$\ln[NO_2$] vs. $$time is not linear, but the plot of $$1/[NO_2$] vs. $$time is linear. What is the order of the reaction with respect to $$NO_2$$?

Accepted Answer

Second order

Chemical Kinetics: Reaction Rates and Rate Laws

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