JEE Main20204 Sep 2020Morning ShiftChemistryChemical KineticsActual
If 75 % of a first order reaction was completed in 90 minutes, 60 % of the same reaction would be completed in approximately (in minutes) _____ (Take: log 2 = 0.30 ; log 2.5 = 0.40 )
Correct answer
0
Step-by-step solution
T = 2 .303 K   log   100 100 − x % T 75 % = 2 .303 K   log   100 25 = 90 T 60 % = 2 .303 K   log   100 40 T 75 % T 60 % = 2 log 2 log 2 .5 ⇒ 90 T 60 % = 2 × 0 .3 0 .4 T 60 % = 90 × 4 6 = 60   min .