Question

A substance undergoes first order decomposition involving two parallel first order reactions as :

k₁ = 1.25 × 10^–4 s^–1

k₂ = 3.80 × 10^–5 s^–1

The mole percentage of B in the products is :

• A. 23.17
• B. 77
• C. 30.16
• D. 69.84

Answer 1

Answer: (B)

77

Answer 2

% of B = $\frac{12.5 \times 10^{- 5}}{(12.5 + 3.8) \times 10^{- 5}}$ × 100 = $\frac{12.5}{16.3}$×100

= 76.68 %