Q112 · CSIR NET Chemistry, December 2012
Paper: CSIR NET December 2012 · Subject: Physical Chemistry · Chapter: Chemical Kinetics · Topic: Chemical Kinetics – General · Marks: 2 · Difficulty: Easy
In atom recombination reactions
(a)$E_a=0,\ \Delta S^{\#}=+\mathrm{ve},\ \Delta H^{\#}=+\mathrm{ve}$
(b)$E_a=0,\ \Delta S^{\#}=-\mathrm{ve},\ \Delta H^{\#}=-\mathrm{ve}$
(c)$E_a=+\mathrm{ve},\ \Delta S^{\#}=-\mathrm{ve},\ \Delta H^{\#}=-\mathrm{ve}$
(d)$E_a=+\mathrm{ve},\ \Delta S^{\#}=+\mathrm{ve},\ \Delta H^{\#}=+\mathrm{ve}$
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
Atom recombination has no barrier (Ea ≈ 0); two particles become one ordered pair (ΔS‡ < 0) and a bond is being formed (ΔH‡ < 0).
Study loop for Chemical Kinetics