Consider the general gas -phase reaction of a molecular substance. A A rightarro
ID: 1018048 • Letter: C
Question
Consider the general gas -phase reaction of a molecular substance. A A rightarrow B At very low pressures many such reactions occur by the following mechanizes. A + A rightarrow A* + A (slow) A* rightarrow B (fast) (A* represents a molecule with sufficient energy to overcome the activation energy barrier.) a. Which of the three reactions above is/are elementary? Show that the proposed mechanism is consistent with reaction 1. The observed reaction. Given the mechanism above, suggest a likely rate law for reaction 1.Explanation / Answer
1. A-------> B
mechanism
A + A -------> A* + A (slow)
A* -----> B (fast)
a. Elementary steps
A + A -------> A* + A (slow)
A* -----> B (fast)
b. A + A -------> A* + A (slow) slow step is called rate determing step.
c. Rate law Rate = K[A]2
2. 2NO2(g) ------> N2O4(g)
Qc = [N2O4]/[NO2]2
= 0.016/(0.016)2
= 62.5
d. 63 >>>> answer