Question

The rate of a reaction is found to double when the concentration of one reactant is quadrupled. What is the order of the reaction with respect to this reactant? ​

Answer 1

Case 1: Identical Reactants

where k is a second order rate constant with units of M-1 min-1 or M-1 s-1. Therefore, doubling the concentration of reactant A will quadruple the rate of the reaction

Answer 2

Given: The rate of a reaction is found to double when the concentration of one reactant is quadrupled.

To find: We have to find the order of the reaction.

Solution:

We know that rate of a reaction is directly proportional to the nth power of the concentration of the reactants.

So, we can write-

$R=K.[C]^n$

Where R is the reaction rate and K is a constant.

Here C is the concentration of the reactant.

The rate of a reaction is found to double when the concentration of one reactant is quadrupled.

Now we can write-

$2R=K.[4C]^n$

Dividing these two equations we get-

$\frac{1}{2} = { \frac{1}{4} }^{n} \\ \frac{1}{2} = { \frac{1}{2} }^{2n} \\ 2n = 1 \\ n = \frac{1}{2}$

Thus, the order of the reaction is 1/2.