In general, can we predict the effect of doubling the concentration of $A$ on the rate of the overall reaction $A+B \longrightarrow C$ ? Can we predict the effect if the reaction is known to be an elementary reaction?

Pure ozone decomposes slowly to oxygen, $2 \mathrm{O}_{3}(g) \longrightarrow 3 \mathrm{O}_{2}(g)$. Use the data provided in a graphical method and determine the order and rate constant of the reaction.

$$\begin{matrix} \text{Time (h)} & \text{0} & \text{}{2.0 \times 10^{3}} & \text{}{7.6 \times 10^{3}} & \text{}{1.00 \times 10^{4}}\\ \text{}{\left[\mathrm{O}_{3}\right](M)} & \text{}{1.00 \times 10^{-5}} & \text{}{4.98 \times 10^{-6}} & \text{}{2.07 \times 10^{-6}} & \text{}{1.66 \times 10^{-6}}\\ \text{Time (h)} & \text{}{1.23 \times 10^{4}} & \text{}{1.43 \times 10^{4}} & \text{}{1.70 \times 10^{4}} & \text{}\\ \text{}{\left[\mathrm{O}_{3}\right](M)} & \text{}{1.39 \times 10^{-6}} & \text{}{1.22 \times 10^{-6}} & \text{}{1.05 \times 10^{-6}} & \text{}\\ \end{matrix}$$

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:

$$\begin{matrix} \text{}{\text { Initial }\left[\mathrm{C}_{3} \mathrm{H}_{5} \mathrm{N}_{3} \mathrm{O}_{9}\right](M)} & \text{4.88} & \text{3.52} & \text{2.29} & \text{1.81} & \text{5.33} & \text{4.05} & \text{2.95} & \text{1.72}\\ \text{t (s)} & \text{300} & \text{300} & \text{300} & \text{300} & \text{180} & \text{180} & \text{180} & \text{180}\\ \text{\\\% Decomposed} & \text{52.0} & \text{52.9} & \text{53.2} & \text{53.9} & \text{34.6} & \text{35.9} & \text{36} & \text{35.4}\\ \end{matrix}$$

Why are elementary reactions involving three or more reactants very uncommon?

Use the PhET Reactions & Rates interactive simulation (http:/lopenstaxcollege.org/I/ 16PHETreaction) to simulate a system. On the "Single collision" tab of the simulation applet, enable the "Energy view" by clicking the " $+"$ icon. Select the first $A+B C \longrightarrow A B+C$ reaction (A is yellow, $\mathrm{B}$ is purple, and $\mathrm{C}$ is navy blue). Using the "angled shot" option, try launching the $A$ atom with varying angles, but with more Total energy than the transition state. What happens when the $A$ atom hits the $B C$ molecule from different directions? Why?

Use the PhET Reactions & Rates interactive simulation (http:/lopenstaxcollege.org/l/ 16PHETreaction) to simulate a system. On the "Single collision" tab of the simulation applet, enable the "Energy view" by clicking the " $+"$ icon. Select the first $A+B C \longrightarrow A B+C$ reaction (A is yellow, $\mathrm{B}$ is purple, and $\mathrm{C}$ is navy blue). Using the "straight shot" default option, try launching the $A$ atom with varying amounts of energy. What changes when the Total Energy line at launch is below the transition state of the Potential Energy line? Why? What happens when it is above the transition state? Why?

The hydrolysis of the sugar sucrose to the sugars glucose and fructose, $\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}+\mathrm{H}_2 \mathrm{O} \longrightarrow \mathrm{C}_6 \mathrm{H}_{12} \mathrm{O}_6+\mathrm{C}_6 \mathrm{H}_{12} \mathrm{O}_6$ follows a first-order rate law for the disappearance of sucrose: rate $=k\left[\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}\right]$ (The products of the reaction, glucose and fructose, have the same molecular formulas but differ in the arrangement of the atoms in their molecules.) (a) In neutral solution, $k=2.1 \times 10^{-11} \mathrm{~s}^{-1}$ at $27^{\circ} \mathrm{C}$ and $8.5 \times 10^{-11} \mathrm{~s}^{-1}$ at $37^{\circ} \mathrm{C}$. Determine the activation energy, the frequency factor, and the rate constant for this equation at $47^{\circ} \mathrm{C}$ (assuming the kinetics remain consistent with the Arrhenius equation at this temperature). (b) When a solution of sucrose with an initial concentration of $0.150 \mathrm{M}$ reaches equilibrium, the concentration of sucrose is $1.65 \times 10^{-7} \mathrm{M}$. How long will it take the solution to reach equilibrium at $27^{\circ} \mathrm{C}$ in the absence of a catalyst? Because the concentration of sucrose at equilibrium is so low, assume that the reaction is irreversible. (c) Why does assuming that the reaction is irreversible simplify the calculation in part (b)?

What is the molar mass of a solution of 5.00 g of a compound in 25.00 g of carbon tetrachloride (bp 76.8 $^{\circ} \mathrm{C}$; Kb = 5.02 $^{\circ} \mathrm{C} / \mathrm{m}$) that boils at 81.5 $^{\circ} \mathrm{C}$ at 1 atm? (a) Outline the steps necessary to answer the question. (b) Solve the problem.

The element Co exists in two oxidation states, Co(II) and Co(III), and the ions form many complexes. The rate at which one of the complexes of $\mathrm{Co}$ (III) was reduced by $\mathrm{Fe}$ (II) in water was measured. Determine the activation energy of the reaction from 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.

Hydrogen iodide, HI, decomposes in the gas phase to produce hydrogen, $\mathrm{H}_2$, and iodine, $\mathrm{I}_2$. The value of the rate constant, $k$, for the reaction was measured at several different temperatures and the data are shown here:

What is the value of the activation energy (in $\mathrm{kJ} / \mathrm{mol}$ ) for this reaction?

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

An elevated level of the enzyme alkaline phosphatase (ALP) in human serum is an indication of possible liver or bone disorder. The level of serum ALP is so low that it is very difficult to measure directly. However, ALP catalyzes a number of reactions, and its relative concentration can be determined by measuring the rate of one of these reactions under controlled conditions. One such reaction is the conversion of p-nitrophenyl phosphate (PNPP) to p-nitrophenoxide ion (PNP) and phosphate ion. Control of temperature during the test is very important; the rate of the reaction increases $1.47$ times if the temperature changes from $30^{\circ} \mathrm{C}$ to $37^{\circ} \mathrm{C}$. What is the activation energy for the ALP-catalyzed conversion of PNPP to PNP and phosphate?

Consider the following reaction in aqueous solution: