Advanced Placement Chemistry 1990 Free Response Questions

7) Consider the following general equation for a chemical reaction.

A(g) + B(g) ---> C(g) + D(g)

(a) Describe the two factors that determine whether a collision between molecules of A and B results in a reaction.

(b) How would a decrease in temperature affect the rate of the reaction shown above? Explain your answer.

(c) Write the rate law expression that would result if the reaction proceeded by the mechanism shown below.

A + B <===> [AB] (fast)

[AB] + B ---> C + D (slow)

(d) Explain why a catalyst increases the rate of a reaction but does not change the value of the equilibrium constant for that reaction.

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