The reaction A 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?
- 1 hour
- 0.5 hour
- 0.25 hour
- 2 hours
Answer
(1) 1 hour
Solution
For a first order reaction, t = 2.303k [A]0[A] — the time for a given fraction of conversion is independent of the initial amount.
Case 1: fraction converted = 0.60.8 = 0.75 (75%) in 1 hour.
Case 2: fraction converted = 0.6750.9 = 0.75 (75%)
Time taken = 1 hour
Answer: (1)