Q: If the average rate of formation of $$O_2 in $$the reaction $$2N_2O(g) \rightarrow 2N_2(g) + O_2$(g) is$$ $$2.0 \times 10$$^{-3}$$\ \text{M/s}$$, what is the average rate of disappearance of $$N_2O$$?

$$4.0 \times 10$$^{-3}$$\ \text{M/s}$$

Q: Which of the following is the correct rate expression for the reaction $$4NH_3(g) + 5O_2(g) \rightarrow 4NO(g) + 6H_2O(g)$$?

$$\text{Rate} = -\frac{1}{4}\frac{\Delta [NH_3$]}{\Delta t} = -\frac{1}{5}\frac{\Delta [O_2$]}{\Delta t} = \frac{1}{4}\frac{\Delta [NO]}{\Delta t} = \frac{1}{6}\frac{\Delta [H_2O]}{\Delta t}$$

Question 1

Which of the following best describes the main focus of chemical kinetics?

Accepted Answer

The study of the rates of chemical reactions and the factors that affect them.

Question 2

Which factor does NOT directly affect the rate of a chemical reaction?

Accepted Answer

Volume of the reaction vessel

Question 3

The rate law for a reaction is given by $$	ext{Rate} = k[A]^2[B]. $$What is the overall order of the reaction?

Accepted Answer

Third order

Question 4

For the reaction $$2A ightarrow B$$, if the rate of disappearance of $$A is$$ $$0.10\ 	ext{M/s}$$, what is the rate of appearance of $$B$$?

Accepted Answer

$$0.05\ 	ext{M/s}$$

Question 5

Which of the following statements about reaction order is TRUE?

Accepted Answer

Reaction order must be determined experimentally.

Question 6

A reaction has the rate law $$	ext{Rate} = k[A][B]^2. If $$the concentration of $$B is $$doubled while $$A is $$kept constant, by what factor does the rate increase?

Accepted Answer

4

Question 7

The instantaneous rate of a reaction at a specific time is determined by:

Accepted Answer

The slope of the tangent to the concentration vs. time curve at that time.

Question 8

Given the reaction $$4NO_2(g) + O_2$(g) ightarrow 2N_2O_5(g)$$, if $$O_2 is $$consumed at a rate of $$0.040\ 	ext{M/s}$$, what is the rate of formation of $$N_2O_5$$?

Accepted Answer

$$0.080\ 	ext{M/s}$$

Question 9

Which of the following is a real-life application of chemical kinetics?

Accepted Answer

Designing dosing schedules for medications based on drug elimination half-life

Question 10

Which CFC listed in the table has the longest atmospheric lifetime, and why is this significant for environmental impact?

Accepted Answer

CFC-115; because its long lifetime means it persists in the atmosphere and can damage the ozone layer for a long time

Question 11

If the average rate of formation of $$O_2 in $$the reaction $$2N_2O(g) ightarrow 2N_2(g) + O_2$(g) is$$ $$2.0 	imes 10$$^{-3}$$\ 	ext{M/s}$$, what is the average rate of disappearance of $$N_2O$$?

Accepted Answer

$$4.0 	imes 10$$^{-3}$$\ 	ext{M/s}$$

Question 12

Which of the following best explains why the reactions that remove CFCs from the atmosphere are a concern?

Accepted Answer

They occur very slowly, allowing CFCs to persist and damage the ozone layer for decades or centuries.

Question 13

In a laboratory experiment, the rate law for the iodination of acetone is found to be $$	ext{Rate} = k[	ext{acetone}]^x[I_2$]^y[H^+]^z. If $$doubling $$[I_2$]$$ does not change the rate, what is the value of $$y$$?

Accepted Answer

0

Question 14

Which of the following is the correct rate expression for the reaction $$4NH_3(g) + 5O_2(g) \rightarrow 4NO(g) + 6H_2O(g)$$?

Accepted Answer

$$	ext{Rate} = -\frac{1}{4}\frac{\Delta [NH_3$]}{\Delta t} = -\frac{1}{5}\frac{\Delta [O_2$]}{\Delta t} = \frac{1}{4}\frac{\Delta [NO]}{\Delta t} = \frac{1}{6}\frac{\Delta [H_2O]}{\Delta t}$$

Question 15

A plot of $$[C_4H_9Cl] vs. $$time is shown. What does the slope of the tangent at $$t = 600\ 	ext{s}$$ represent?

Accepted Answer

The instantaneous rate of disappearance of $$C_4H_9Cl at$$ $$t = 600\ 	ext{s}.$$

Question 16

Which of the following best describes a catalyst's effect on a chemical reaction?

Accepted Answer

It increases the rate constant by providing an alternative pathway with lower activation energy.

Question 17

If a reaction is zeroth order with respect to a reactant, what happens to the rate if the concentration of that reactant is doubled?

Accepted Answer

The rate remains unchanged.

Chemical Kinetics: Reaction Rates, Stoichiometry, and Rate Laws

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