For an unknown chemical reaction, experimental kinetic data shows that its half-life is directly pro — Chemical Kinetics Chemistry Question

💡 Solution & Explanation

The general relation between half-life and initial concentration for an $n^{\text{th}}$ order reaction is $t_{1/2} \propto a^{1-n}$. We are given $t_{1/2} \propto a^{-2}$. By directly equating the exponents, $1 - n = -2 \Rightarrow n = 3$. Therefore, it is a third-order reaction.