Q. For the two gaseous reactions, following data are given $A \rightarrow B;k_{1} = 10^{10}e^{- 20,000/T}$ $C \rightarrow D;k_{2} = 10^{12}\ e^{- 24,606/T}$ The temperature at which $k_{1}$ becomes equal to $k_{2}$ is

A) 400 K
B) 1000 K
C) 800 K
D) 1500 K
Explanation

(b)
Given, $k_{1}10^{10}e^{- 20,000/T}$
$k_{2} = 10^{12}e^{- 24,606/T}$
$k_{1} = k_{2}$
$10^{10}e^{- 20,000/T} = 10^{12}e^{- 24,606/T}$
$e^{\frac{- 20,000}{T} + \frac{24,606}{T}} = 10^{2}$
$e^{\frac{4,606}{T}} = 10^{2}$
On taking log both sides,
$\frac{4606}{2.303T} = \log 10^{2}$
$2\log{10 \times T = \frac{4606}{2.303}}$
$T = \frac{4606}{2.303 \times 2}$
$= \frac{4606}{4.606} = 1000\ K$

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.