Question

The overall order of the reaction is _________. (Round off to the Nearest Integer) based on the NO and Cl$_2$ data.

Hint:

If concentration doubles and rate doubles, order is 1. If rate quadruples, order is 2.

Answer 1

Correct Answer: 3

Step 1: Rate $= k [NO]^m [Cl_2]^n$.
Step 2: From runs 1 and 2, $[NO]$ is constant, $[Cl_2]$ doubles, and rate $\approx$ doubles ($0.35/0.18 \approx 2$). So, $n = 1$.
Step 3: From runs 2 and 3, $[Cl_2]$ is constant, $[NO]$ doubles, and rate increases 4 times ($1.40/0.35 = 4$). So, $2^m = 4 \implies m = 2$.
Step 4: Overall order $= m + n = 2 + 1 = 3$.