Question

Which is more stable `cl-` or chlorine free redical ?

Answer 1

The neutral `Cl*` radical should be far more reactive than `Cl^-`, chloride anion.

Explanation:

The chlorine radical has 7 valence electrons, and in the very fact of making a `"2-centre, 2 electron bond"` it would generate another radical to continue the chain.

`Cl* + CH_4 rarr *CH_3 + H-Cl` etc.

Answer 2

When we say "chlorine wants to gain one electron", we speak of the radical atom.

Chlorine as a free radical, `"Cl"cdot`, is the chlorine atom that we say has 7 valence electrons and wants its 8th to form an octet.

Chlorine as an anion, `"Cl"^(-)`, has already gained its 8th valence electron and has an argon-like electron configuration:

`1s^2 2s^2 2p^6 3s^2 3p^6`

So, `"Cl"cdot`, chlorine radical, is less stable, and `"Cl"^(-)`, chlorine ion, is more stable.