Question

What kind of organic reaction can form fluoromethane `CH_3F`, from methane?

Answer 1

Halogen exchange reactions:

`H_3C-X + F_2 rarr H_3C-F + F-X`

Explanation:

`H_4C +Cl_2 rarrH_3C-Cl + HCl`

`H_3C-Cl + F_2 rarr H_3C-F + F-Cl`

Why can't it be synthesized directly? Possibly, it can, but the strength of the `C-F` bond probably imposes an unacceptably high risk of runaway reaction. Fluorine is the most reactive element on the Periodic Table.

The synthesis must be a messy, smelly business. Special containers would be needed to cope with the corrosive nature of the hydrogen halides.