For the elementary bimolecular gas-phase reaction structurally defined as , the total volume of the — Chemical Kinetics Chemistry Question

💡 Solution & Explanation

Since it is explicitly stated as an elementary process, the exact rate law mirrors the stoichiometry: $\text{Rate} = k[A]^2[B]^1$. Dropping the volume to $1/3$ identically forces the molar concentration of every single gas to spike by exactly 3 times. The new rate equals $k(3[A])^2(3[B]) = 27 \times k[A]^2[B]$, which is a 27-fold increase.