Question

A substance undergoes first order decomposition. The decomposition follows two parallel first order reactions as :

The percentage distribution of B and C are :

• A. 80% B and 20% C
• B. 76.83% B and 23.17% C
• C. 90% B and 10% C
• D. 60% B and 40% C

Answer 1

The correct option is B 76.83% B and 23.17% C

$\%\left[B\right]=\frac{K_1}{K_1+K_2}\times 100$
$=\frac{12.6\times {10}^{-4}}{12.6\times {10}^{-4}+3.8\times {10}^{-4}}\times 100$
$=76.83\%$
$\%\left[c\right]=100-76.83=23.17\%$