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 that the rate of appearance of B is $$0.0070\ \mathrm{M/s}$$?

$$-7.0 \times 10$$^{-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 interval?

Accepted Answer

$$0.023\ \mathrm{M/s} (as a $$negative 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 torr/min, what is the rate of change of the total pressure in the vessel?

Accepted Answer

Increasing at a rate of 28 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

Which experiment would best help you determine the order of a reaction with respect to $$[OH^-] in $$the reaction $$2ClO_2(aq) + 2OH^-(aq) \rightarrow $$ClO_3$$^-(aq) + $$ClO_2$$^-(aq) + H_2O(l)$$?

Accepted Answer

Vary $$[OH^-]$$ while keeping $$[$$ClO_2$$]$$ constant

Question 7

A reaction is found to be zero order in $$[A]. $$Which of the following plots will yield a straight line?

Accepted Answer

$$[A] vs. $$time

Question 8

For a first-order reaction, which integrated rate law equation is correct?

Accepted Answer

$$\ln A_t - \ln A_0$ = -kt$$

Question 9

A student collects the following data for the decomposition of $$NO_2 at 300$$°C:

Time (s): 0, 50, 100, 200, 300
$$[NO_2$] (M$$): 0.01000, 0.00787, 0.00649, 0.00481, 0.00380

Which plot would be linear if the reaction is second order in $$NO_2$$?

Accepted Answer

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

Question 10

Which of the following statements about the rate constant $$k is $$TRUE?

Accepted Answer

Its units depend on the overall reaction order

Question 11

A catalyst increases the rate of a reaction by:

Accepted Answer

Lowering the activation energy

Question 12

Which of the following is a plausible value for the rate of disappearance of A from 40 to 60 s, given that the rate of appearance of B is $$0.0070\ \mathrm{M/s}$$?

Accepted Answer

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

Question 13

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

Accepted Answer

The rate is independent of the concentration of reactant

Question 14

Beer’s Law is used in spectrophotometry to relate absorbance to concentration. Which equation represents Beer’s Law?

Accepted Answer

$$A = \epsilon bc$$

Question 15

If a reaction is first order in $$A$$ and zero order in $$B$$, what is the overall order of the reaction?

Accepted Answer

First order

Question 16

Which of the following is true for a reaction with the rate law $$	ext{Rate} = k[A][B]$$?

Accepted Answer

Doubling both $$[A]$$ and $$[B]$$ will quadruple the rate

Question 17

Which of the following best explains why the rate of a reaction generally increases with temperature?

Accepted Answer

More molecules have enough energy to overcome the activation energy barrier

Question 18

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 19

Which of the following is a characteristic of a heterogeneous reaction?

Accepted Answer

Reactants are in different phases

Chemical Kinetics: Reaction Rates and Rate Laws

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