Paper: CSIR-NET December 2019 · Subject: Physical Chemistry · Chapter: Chemical Kinetics · Topic: Chemical Kinetics – General · Marks: 2 · Difficulty: Medium
If the rate constant for a base catalyzed ester hydrolysis reaction is $0.20 \mathrm{L} \mathrm{mol}^{-1} \mathrm{s}^{-1}$, half-life (in s) of the ester (Given $[\text { ester }]_{0}=[\text { base }]_{0}=0.05 \mathrm{mol} \mathrm{L}^{-1}$ ) would be closest to
(a)40
(b)100
(c)140
(d)200
Answer
Answer: B ✓ checked by 4AB · confidence high
The source book printed no answer; this one was worked out and checked — see the explanation.
Explanation
Second order with equal concentrations: t₁/₂ = 1/(k[A]₀) = 1/(0.20 × 0.05) = 100 s.