Question

For reaction $aA\to xP$, when $\left[A\right]=2.2mM$, the rate was found to be $2.4mM{s}^{-}$. On reducing concentration of $A$ to half, the rate changes to $0.6mM{s}^{-1}$. The order of reaction with respect to $A$ is:

• A. $1.5$
• B. $2.0$
• C. $2.5$
• D. $3.0$

Answer 1

Answer: (B)

$2.0$

According to the given data, when the concentration of reactant is reduced to half its initial value, the rate is reduced by $\frac{2.4}{0.6}=4$ times.
It means rate $\propto {\left[reactant\right]}^2$
So, the order of reaction$=2$