Question

In a reaction $A\to B,$ when the concentration of reactant is made 8 times, the rate got doubled. The order of reaction is

• A. $\frac{1}{3}$
• B. 1
• C. $\frac{1}{2}$
• D. 2

Answer 1

The correct option is A $\frac{1}{3}$

The given relation is: $A\to B$

Let concentration of $\left[A\right]=c_1$ and initial rate as concentration is made 8 times.

From $c_1$ to $8\times c_1=8c_1$

Rate will becomes $2\times r_1=r_2$

Order $\Rightarrow \frac{\log \frac{r_2}{r_1}}{\log \frac{c_2}{c_1}}=\frac{\log \frac{2r_1}{r_1}}{\log \frac{8c_1}{c_1}}=\frac{\log 2}{\log 8}$

$=\frac{\log 2}{3\log 2}=\frac{1}{3}$