JEE Main · 2021 · 17 Mar 2021 · Shift 2 · Chemical Kinetics

The reaction

2 A + B_{2} \to 2 AB

is an elementary reaction.
For a certain quantity of reactants, if the volume of the reaction vessel is reduced by a factor of 3, the rate of reaction increases by a factor of ______.
(Round off to the nearest integer).

Answer: 27

Solution

For an elementary reaction, rate =

k [A]^{2} [B_{2}]

. When volume is reduced by a factor of 3, all concentrations increase by a factor of 3. New rate =

k (3 [A])^{2} (3 [B_{2}]) = k \cdot 9 [A]^{2} \cdot 3 [B_{2}] = 27 k [A]^{2} [B_{2}]

. Therefore, the rate increases by a factor of 27.

JEE Main · 2021 · 17 Mar 2021 · Shift 2 · Integer answer

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