Question

multiple choice 2 points
which of the following is true for the initiation step of a free radical chlorination reaction?
δh°>0 and δs°>0
δh°>0 and δs°<0
δh°=0 and δs°=0
δh°<0 and δs°<0
δh°<0 and δs°>0

Explanation:

Step1: Understand initiation step

In free - radical chlorination initiation, a chlorine - chlorine bond breaks to form two chlorine radicals.

Step2: Analyze enthalpy change

Breaking a bond requires energy input, so $\Delta H^{\circ}>0$ (endothermic).

Step3: Analyze entropy change

One molecule (Cl - Cl) forms two radicals, increasing the number of particles and randomness, so $\Delta S^{\circ}>0$.

Answer:

A. $\Delta H^{\circ}>0$ and $\Delta S^{\circ}>0$