Question

The reaction $A\to B$ follows first order kinetics. The time taken for 0.8 mole of A to produce 0.6 mole of B is 1 hour. What is the time taken for conversion of 0.9 mole of A to produce 0.675 mole of B?

• A. 1 hour
• B. 0.5 hour
• C. 0.25 hour
• D. 2 hours

Answer 1

The correct option is A 1 hour

Case : 1 :- Fraction of 'A' reacted = $\frac{0.6}{0.8}=\frac{3}{4}$

Case : II :- Fraction of 'A' reacted = $\frac{0.675}{0.9}=\frac{3}{4}$

For a first order reaction, time taken for the same fraction of reaction is independent of initial concentration.