Question

For a reaction $E_a=0,K=4.2\times {10}^{5}se{c}^{-1}$ at 300 K, the value of K at 310 K will be:

• A. $4.2\times {10}^{5}se{c}^{-1}$
• B. $8.4\times {10}^{5}se{c}^{-1}$
• C. $8.4\times {10}^{-5}se{c}^{-1}$
• D. $4.2\times {10}^{-5}se{c}^{-1}$

Answer 1

Answer: (A)

$4.2\times {10}^{5}se{c}^{-1}$

From Arrhenius equation:

$log\frac{k_2}{k_1}=\frac{E_a}{2.303R}\left[\frac{T_2-T_1}{T_1{T}_2}\right]$

$log\frac{k_2}{4.2\times {10}^{5}se{c}^{-1}}=\frac{0}{2.303R}\left[\frac{T_2-T_1}{T_1{T}_2}\right]=0$

$\frac{k_2}{4.2\times {10}^{5}se{c}^{-1}}={10}^0=1$

$k_2=4.2\times {10}^{5}se{c}^{-1}$

Since the activation energy is zero, the rate constant is independent of the change in temperature.

Hence, option A is correct.