Q76 · CSIR-NET Chemistry, December 2012

Paper: CSIR-NET December 2012 · Subject: Physical Chemistry · Chapter: Chemical Kinetics · Topic: Rate Laws Order · Marks: 2 · Difficulty: Medium

If the concept of half-life is generalized to quarter-life of a first order chemical reaction, it will be equal to

(a)$\frac{\ln 2}{\mathrm{k}}$

(b)$\frac{\ln 4}{\mathrm{k}}$

(c)$\frac{4}{\mathrm{k}}$

(d)$\frac{1}{4 \mathrm{k}}$

Answer

Answer: B ✓ checked by 4AB · confidence medium

The source book printed no answer; this one was worked out and checked — see the explanation.

Explanation

Time for the concentration to fall to one quarter: [A]₀/4 = [A]₀e^{−kt} ⇒ t = ln 4/k (= 2 t₁/₂).

Study loop for Chemical Kinetics