Consider the following hypothetical data collected in two studies of the reaction
2A(g) + 2B(g) †’ C(g) + 2D(g)

In experiment 1, [B] = 10.0 M. In experiment 2, [B] = 20.0 M.

a. Use the concentration versus time data to determine the rate law for the reaction.
b. Solve for the rate constant k for the reaction. Include units.
c. Calculate the concentration of A in experiment 1 at t = 30. s.
d. The following three mechanisms are proposed for this reaction:
i. 2B ‡Œ B2 (Fast equilibrium)
B2 + A †’ E + D (Slow)
E + A †’ C + D (Fast)
ii. A + B †’ D + F (Slow)
F + B †’ C + G (Fast)
G + A †’ D (Fast)
iii. A + 2B †’ E + D (Slow)
E + A †’ C + D (Fast)
Choose the best mechanism(s). Include an explanation of which mechanism(s) you exclude and why. If you believe two (or even all three) mechanisms are equally good, explain why.

Experiment Experi Time (s) A (mol/L.) A] (mol/L) 10. 20 30. 40 1.0 x 10-2 8.4 X 10- 7.1 x 10- 1.0 x 102 5.0 x 10-3 2.5 X 103 1.3 x 10-3 6.3 x 10-4 5.0 x 10 -diA] Ratedt