Which one of the following reactions is not an example of redox reaction ?

$C{l}_2 + 2{\mathrm{H}}_2\mathrm{O} + {\mathrm{SO}}_2 \to 4{\mathrm{H}}^{+} + {\mathrm{SO}}^{4-} 2{\mathrm{Cl}}^{-}$

${\mathrm{Cu}}^{++} + \mathrm{Zn} \to {\mathrm{Zn}}^{++} + \mathrm{Cu}$

$2{\mathrm{H}}_2 + {\mathrm{O}}_2 \to 2{\mathrm{H}}_2\mathrm{O}$

$\mathrm{HCl} + {\mathrm{H}}_2\mathrm{O} \to {\mathrm{H}}_3{\mathrm{O}}^{-} + \mathrm{C}{l}^{-}$