Question

Draw the electron-pushing mechanism for each radical reaction below. Identify each step as initiation, propagation, or termination.

(a)

b)

c)

Short answer

a.

b.

c.

Step-by-step solution

Free radical reaction

The reaction which involves free radicals is called a free radical reaction.

The free radical reaction is completed in three-step. The first step of the reaction is an initiation then the second step is propagation and the third step is termination.

Mechanism of reaction free radical reaction

Initiation Step:

Radical reactions are initiated by light. The reaction is also initiated by UV light. In the first step$\text{Cl-Cl}$bond break, homolytically and $\text{Cl}$free radical is formed. Also, cyclopentane and hydrogen-free radicals form by breaking the $\text{C-H}$bond of the cyclopentane ring.

Propagation step:

In this step, the radicals which are generated in the initiation step collide with each other and new radicals are generated.

Termination step:

When two free radicals collide with each other then the chain is terminated.

Free radical reactions

a.

mechanism

Mechanism of Reaction a

b.

mechanism

c.

mechanism

Mechanism of Reaction c