Question

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?

(a) 1 hour
(b) 0.5 hour
(c) 0.25 hour
(d) 2 hours

Answer 1

(a) 1 hour

The fraction of A reacted in each case is same (0.2 / 0.8 = 1/4),

(0.9 – 0.675)/ 0.90 = 0.225 / 0.90 = 1/4.

Hence, time taken is same.