Question

$A$ substance undergoes first order decomposition. The decomposition follows two parallel first order reactions given above with rate constants:
$k_1=1.28\times {10}^{-4}{sec}^{-1}$
$k_2=3.2\times {10}^{-5}{sec}^{-1}$
The percentage distribution of $B$ and $C$ are:

• A. $75$% $B$ and $25$% $C$
• B. $20$% $B$ and $80$% $C$
• C. $60$% $B$ and $40$% $C$
• D. $80$% $B$ and $20$% $C$

Answer 1

The correct option is D $80$% $B$ and $20$% $C$

Percent distribution of B=$\frac{k_1}{K_1+K_2}\times 100$

$=80$%

And percent distribution of C=$\frac{K_2}{K_1+K_2}\times 100$

$=20$%