Question

For the reaction 2 A + B ---> Products, the following initial rate data was collected? [A] [B] Initial Rate 0.01 M 0.01 M 0.002 M/sec 0.03 M 0.02 M 0.0024 M/sec 0.03 M 0.01 M 0.006 M/sec

[A] [B] Initial Rate
0.01 M 0.01 M 0.002 M/sec
0.03 M 0.02 M 0.024 M/sec
0.03 M 0.01 M 0.006 M/sec

(a) What is the order of reaction for each reactant? Overall?
(b) What are the units of the rate constant?
(c) What is the value of the rate constant?

Answer 1

a. Overall third order, A to the first, B to the second
b. `mol^-2dm^6s^-1`
c. `2000`

Explanation:

When A is tripled in trial 3 from trial 1, and B is kept constant the rate also triples, so A is to the first order.

When A is kept constant from trial 3 to trial 2 but B is doubled, the rate quadruples, therefore B is to the second order.

Determining K
`K=(0.002M/sec)/((0.01M)*(0.01M)^2)`