Question

If the 60% of first order reaction was completed in 60 minutes, 50 % of the same reaction would be completed in approximately (log 4 = 0.6, log 5 =0.69)
1- 45 mins
2- 60 mins
3-40 mins
4- 50 mins.

Answer 1

30min.

first order integration form k= 2.303log(a/a-x)/t half life = 0.693/k, k is rate constant

a= intial concentration =100, a-x = 40, t= 60min.