JEE Main 2025 — Chemical Kinetics Question with Solution

$\begin{aligned} & \text { rate }=\mathrm{k}_2[\mathrm{~A}]\left[\mathrm{B}_2\right] \ldots \ldots \\ & \left(\frac{\mathrm{k}_1}{\mathrm{k}_{-1}}\right)=\left(\frac{[\mathrm{A}]^2}{\left[\mathrm{~A}_2\right]}\right) \\ & \Rightarrow[\mathrm{A}]=\sqrt{\frac{\mathrm{k}_1}{\mathrm{k}_{-1}}} \cdot \sqrt{\left[\mathrm{~A}_2\right]} \end{aligned}$ Substituting in (1) ; we get $\begin{array}{rl}& \text{ Rate }={\mathrm{k}}_2\sqrt{\frac{{\mathrm{k}}_1}{{\mathrm{k}}_{-1}}}\cdot {\left[{\mathrm{A}}_2\right]}^{\frac{1}{2}}\cdot \left[{\mathrm{B}}_2\right]\\ & \therefore \text{ order }=\left(\frac{3}{2}\right)=1.5\end{array}$