Free radical reactions

Generally free radical reactions take place at different conditions.

$\mathrm{i}) \mathrm{h\vartheta } \mathrm{or} \mathrm{Sun} \mathrm{light}$

$\mathrm{ii}) {\mathrm{H}}_2{\mathrm{O}}_2$

$\mathrm{iii}) {\mathrm{Ph}}_2{\mathrm{O}}_2$

$\mathrm{iv}){\mathrm{O}}_2$

Note: Ph = phenyl, ${\mathrm{C}}_6{\mathrm{H}}_5^{-}$