Provided the following experimental data, determine the correct rate law:

Question

Provided the following experimental data, determine the correct rate law:

Rate (mol / L-s)	A (mol/L)	B (mol/L)
2.87 * 10-4	0.012	0.0207
7.16 * 10-3	0.060	0.0621
2.87 * 10-4	0.012	0.0621

A. Rate = 0.0238 [A] B. Rate = 1.15 [A]2 C. Rate = 55.6 [A] D. Rate = 1.99 [A]2 E. Rate = 0.667 [B]2

Answer 1

Comparing first and third lines, [A] remains constant at 0.012 M and [B] is tripled from 0.0207 M to 0.0621 M. The rate did not change, so we conclude the reaction is ZERO order in B.

Comparing first and second lines, [A] increases by 5 times from 0.012 M to 0.060 M. The rate increased by 25 times from 2.87x10^-4 M to 7.16x10^-3 M. This tells us the reaction is SECOND order in A.

The rate law can be written as Rate = k[A]²

Solving for k, we have

2.87x10^-4 = k[0.012]² = 1.44x10^-4 k

k = 1.99

The rate can then be expressed as

Rate = 1.99 [A]² ANSWER D