Chapter 12, Problem 47P

(a)

Interpretation Introduction

Interpretation:

The $\text{ΔH}$ value for the given reaction should be calculated.

Concept introduction:

Radical or free radical: unpaired valence electron of an atom, molecule, or ion is called as radical.

Bond strength is depends on the formation of the radical, if the radical is involving in resonance which is weakest bond strength.

The $\text{ΔH}$ can be calculated by using following formula,

${\text{ΔH}}^{\text{o}}\text{=}\text{bond}\text{broken-}\text{bonds}\text{formed}$

(b)

Interpretation Introduction

Interpretation:

The sum of the $\text{ΔH}$ value for the given reaction should be calculated.

Concept introduction:

Radical or free radical: unpaired valence electron of an atom, molecule, or ion is called as radical.

Bond strength is depends on the formation of the radical, if the radical is involving in resonance which is weakest bond strength.

Propagation: In this stage, two steps are involving hydrogen abstraction and halogen abstraction (no change in the number of free radicals)

(c)

Interpretation Introduction

Interpretation:

The reason why both the above reactions from subpart (a) and (b) have same $\text{ΔH}$ value.has to be explained.

Concept introduction:

Radical or free radical: unpaired valence electron of an atom, molecule, or ion is called as radical.

Bond strength is depends on the formation of the radical, if the radical is involving in resonance which is weakest bond strength.

Propagation: In this stage, two steps are involving hydrogen abstraction and halogen abstraction (no change in the number of free radicals)