In terms of collision theory, to which of the following is the rate of a chemical reaction proportional? (a) the change in free energy per second (b) the change in temperature per second (c) the number of collisions per second (d) the number of product molecules

The rate constant at $325^{\circ} \mathrm{C}$ for the decomposition reaction $\mathrm{C}_4 \mathrm{H}_8 \longrightarrow 2 \mathrm{C}_2 \mathrm{H}_4$ is $6.1 \times 10^{-8} \mathrm{~s}$, and the activation energy is $261 \mathrm{~kJ}$ per mole of $\mathrm{C}_4 \mathrm{H}_8$. Determine the frequency factor for the reaction.

In an experiment, a sample of $\mathrm{NaClO}_3$ was $90 \%$ decomposed in $48 \mathrm{~min}$. Approximately how long would this decomposition have taken if the sample had been heated $20^{\circ} \mathrm{C}$ higher? (Hint: Assume the rate doubles for each 10 ${ }^{\circ} \mathrm{C}$ rise in temperature.)

The rate of a certain reaction doubles for every $10^{\circ} \mathrm{C}$ rise in temperature. (a) How much faster does the reaction proceed at $45^{\circ} \mathrm{C}$ than at $25^{\circ} \mathrm{C}$ ? (b) How much faster does the reaction proceed at $95^{\circ} \mathrm{C}$ than at $25^{\circ} \mathrm{C}$ ?

How does an increase in temperature affect rate of reaction? Explain this effect in terms of the collision theory of the reaction rate.

Describe how graphical methods can be used to determine the activation energy of a reaction from a series of data that includes the rate of reaction at varying temperatures.

Account for the relationship between the rate of a reaction and its activation energy.

What is the activation energy of a reaction, and how is this energy related to the activated complex of the reaction?

When every collision between reactants leads to a reaction, what determines the rate at which the reaction occurs?

Chemical reactions occur when reactants collide. What are two factors that may prevent a collision from producing a chemical reaction?

A study of the rate of the reaction represented as $2 A \longrightarrow B$ gave the following data:

(a) Determine the average rate of disappearance of $A$ between $0.0 \mathrm{~s}$ and $10.0 \mathrm{~s}$, and between $10.0 \mathrm{~s}$ and $20.0 \mathrm{~s}$.

(b) Estimate the instantaneous rate of disappearance of $A$ at $15.0$ s from a graph of time versus [A]. What are the units of this rate?

(c) Use the rates found in parts (a) and (b) to determine the average rate of formation of $B$ between $0.00 \mathrm{~s}$ and $10.0 \mathrm{~s}$, and the instantaneous rate of formation of $B$ at $15.0 \mathrm{~s}$.

For the past 10 years, the unsaturated hydrocarbon 1,3-butadiene $\left(\mathrm{CH}_2=\mathrm{CH}-\mathrm{CH}=\mathrm{CH}_2\right)$ has ranked 38 th among the top 50 industrial chemicals. It is used primarily for the manufacture of synthetic rubber. An isomer exists also as cyclobutene: C1=CCC1 The isomerization of cyclobutene to butadiene is first-order and the rate constant has been measured as $2.0 \times 10^{-4}$ $\mathrm{s}^{-1}$ at $150^{\circ} \mathrm{C}$ in a $0.53-\mathrm{L}$ flask. Determine the partial pressure of cyclobutene and its concentration after $30.0$ minutes if an isomerization reaction is carried out at $150^{\circ} \mathrm{C}$ with an initial pressure of 55 torr.

Nitroglycerine is an extremely sensitive explosive. In a series of carefully controlled experiments, samples of the explosive were heated to $160^{\circ} \mathrm{C}$ and their first-order decomposition studied. Determine the average rate constants for each experiment using the following data:

Recently, the skeleton of King Richard III was found under a parking lot in England. If tissue samples from the skeleton contain about $93.79 \%$ of the carbon-14 expected in living tissue, what year did King Richard III die? The half-life for carbon- 14 is 5730 years.