Question

Calculate the time time required for completion of 60% of the reaction if 20min

Answer 1

half life period =20minutes=> 0.693/k =20 minutes => k=0.693/20 per minute. Time required for 60% of the reaction to complete = 2.303/k log Ao/A
where k is rate constant and Ao is initial % or concentration present and A is final % left or concentration. So time taken =2.303/(0.693/20) log5/3 = 10/3(20)(log 5-log 2) =200/3(0.6990-0.301)
= 200/3(0.398) =79.6/3 =26.53 minutes approximately.