A reaction is second order with respect to a reactant. If the concentration of the reactant is increased by 1.5 times, the rate of the reaction

Increases by 2.25 times.

The correct answer is Option (2) → Increases by 2.25 times.

For a reaction of order $n$,

$\text{Rate} \propto [A]^n$

Here, the reaction is second order $\rightarrow n = 2$.

Calculation

Let original concentration $= [A]$

New concentration $= 1.5[A]$

$\text{New rate} = k(1.5[A])^2 \text{}$

$= k \times 2.25[A]^2 \text{}$

$= 2.25 \times \text{original rate}$