Q.
A first order reaction has a rate constant of 2.303×10−3 s−1. The time required for 40g of this reactant to reduce to 10 g will be-
[Given that log10 2 = 0.3010
For a first order reaction; t1/2=K0.693 t1/2=2.303×10−30.693=301s
The time required for 40g of reactant to reduce to 10g t75%=2×t1/2 t75%=2×301=602s