Cobra venom helps the snake secure food by binding to acetylcholine receptors on the diaphragm of a bite victim, leading to the loss of function of the diaphragm muscle tissue and eventually death. In order to develop more potent antivenins, scientists have studied what happens to the toxin once it has bound the acetylcholine receptors. They have found that the toxin is released from the receptor in a process that can be described by the rate law Rate = k [acetylcholine receptortoxin complex] If the activation energy of this reaction at 37.0C is 26.2 kJ/mol and A = 0.850 s1. what is the rate of reaction if you have a 0.200M solution of receptor-toxin complex at 37.0C?

Consider the reaction of ozone and nitrogen monoxide to form nitrogen dioxide and oxygen. O3(g) + NO(g) NO2(g) + O2(g) Which of the following orientations for the collision between ozone and nitrogen monoxide could perhaps lead to an effective collision between the molecules? (a) (b) (c) (d)

Candle wax is a mixture of hydrocarbons. In the reaction of oxygen with candle w ax in Figure 11.2, the rate of consumption of oxygen decreased with time after the flask was covered, and eventually' the flame went out. From the perspective of the kinetic-molecular theory, describe what is happening in the flask. FIGURE 11.2 When a candle burns in a closed container, the flame will diminish and eventually go out. As the amount of oxygen present decreases, the rate of combustion will also decrease. Eventually, the rate of combustion is no longer sufficient to sustain the flame even though there is still some oxygen present in the vessel.

Ozone, O3, in the Earths upper atmosphere decomposes according to the equation 2 O3(g) 3 O2(g) The mechanism of the reaction is thought to proceed through an initial fast, reversible step followed by a slow, second step. Step 1: Fast, reversible O3(g) O2(g) + O(g) Step 2: Slow O3(g) + O(g) 2 O2(g) (a) Which of the steps is rate-determining? (b) Write the rate equation for the rate-determining step

Kinetics I Consider the hypothetical reaction A(g) + 2B(g) h C(g). The four containers below represent this reaction being run with different initial amounts of A and B. Assume that the volume of each container is 1.0 L. The reaction is second order with respect to A and first order with respect to B. a Based on the information presented in the problem, write the rate law for the reaction. b Which of the containers, W, X, Y, or Z, would have the greatest reaction rate? Justify your answer. c Which of the containers would have the lowest reaction rate? Explain. d If the volume of the container X were increased to 2.0 L, how would the rate of the reaction in this larger container compare to the rate of reaction run in the 1.0-L container X? (Assume that the number of A and B atoms is the same in each case.) e If the temperature in container W were increased, what impact would this probably have on the rate of reaction? Why? f If you want to double the rate of reaction in container X, what are some things that you could do to the concentration(s) of A and B? g In which container would you observe the slowest rate of formation of C? h Assuming that A and B are not in great excess, which would have the greater impact on the rate of reaction in container W: removing a unit of B or removing a unit of A? Explain. i Describe how the rate of consumption of A compares to the rate of consumption of B. If you cannot answer this question, what additional information do you need to provide an answer? j If the product C were removed from the container as it formed, what effect would this have on the rate of the reaction?

Explain what is meant by the average rate of a reaction.

The reaction 2 NO(g) + 2 H2(g) N2(g) + 2 H2O(g) was studied at 904 C, and the data in the table were collected. (a) Determine the order of the reaction for each reactant. (b) Write the rate equation for the reaction. (c) Calculate the rate constant for the reaction. (d) Find the rate of appearance of N2 at the instant when [NO] = 0.350 mol/L and [H] = 0.205 mol/L.

Isomerization of CH3NC occurs slowly when CH3NC is heated. CH3NC(g) CH3CN(g) To study the rate of this reaction at 488 K, data on [CH3NC] were collected at various times. Analysis led to the following graph. (a) What is the rate law for this reaction? (b) What is the equation for the straight line in this graph? (c) Calculate the rate constant for this reaction. (d) How long does it take for half of the sample to isomerize? (e) What is the concentration of CH3NC after 1.0 104 s?

Experiments show that the reaction of nitrogen dioxide with fluorine, 2 NO2(g) + F2(g) —* 2 FNO2(g) has the rate law Rate = *[NO2][FJ The reaction is thought to occur in two steps. Step 1: NO2(g) + F,(g) —* FNO,(g) + F(g) Step 2: NO2(g) + F(g) — FNO2(g) Show that the sum of this sequence of reactions gives the balanced equation for the overall reaction. Which step is rate determining?