21. A first order reaction takes 40 min for 30% decomposition. Calculate t1/2 for first order reaction ((log 7 = 0.8451, log 10 = 1)

21. A first order reaction takes 40 min for 30% decomposition. Calcula

1.	21. A first order reaction takes 40 min for 30% decomposition. Calculate t1/2 for first order reaction ((log 7 = 0.8451, log 10 = 1)
Answer» 77.7 minutes is the answerExplanation:LET a M be the initial concentration. After 40 minutes, the concentration is a−30a/ 100 =0.70a. k= 2.303/t log [A]) − / [A]k= 2.303/40 log a/ 0.70a k=8.92×10^−3 /min The half life PERIOD, t 1/2 = 0.693/k= 0.693/8.92×10 ^-3/min=77.7 MINUTE hope this HELPS u