Question

What is the activation energy for the decomposition of $N_2O_5$ as
$N_{2}O_{5}\rightleftharpoons 2NO_{2}+\frac{1}{2}O_{2}$
If the values of the rate constants are $3.45\times10^{-5}$ and $6.9\times10^{-3}$ at $27^{\circ}C$ and $67^{\circ}C$ respectively

• A. $102 \times 10^2 kJ$
• B. $488.5 \,kJ$
• C. $112\, kJ$
• D. $14.7\, kJ$

Answer 1

Answer: (D)

log$\frac{6.9\times10^{-3}}{3.45\times10^{-3}}=\frac{E_{a}\left(340-300\right)}{8.314\times10^{-3}\times2.303\times300\times340}$
$\therefore E_{a}=\frac{0.301\times8.314\times10^{-3}\times2.303\times300\times340}{40}=14.7 KJ$