Q79 · CSIR-NET Chemistry, June 2015

Paper: CSIR-NET June 2015 · Subject: Physical Chemistry · Chapter: Chemical Kinetics · Topic: Chemical Kinetics – General · Marks: 2 · Difficulty: Medium

For a given ionic strength, (I) rate of reaction is given by $\log \frac{\mathrm{k}}{\mathrm{k}_{0}}=-4 \times 0.51 \mathrm{I}^{1 / 2}$. Which of the following reactions follows the above equation?
(a)$\mathrm{S}_{2} \mathrm{O}_{8}^{2-}+\mathrm{I}^{-}$
(b)$\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{Br}^{2+}+\mathrm{OH}^{-}$
(c)$\mathrm{CH}_{3} \mathrm{COOC}_{2} \mathrm{H}_{5}+\mathrm{OH}^{-}$
(d)$\mathrm{H}^{+}+\mathrm{Br}^{-}+\mathrm{H}_{2} \mathrm{O}_{2}$
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
The Brønsted–Bjerrum relation is log(k/k₀) = 2A·z_Az_B√I = 1.02 z_Az_B√I. −4 × 0.51 means z_Az_B = −2, which is [Co(NH₃)₅Br]²⁺ + OH⁻ (b).

Study loop for Chemical Kinetics

1. Practise the PYQsPrevious-year questions, with answers

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