Which one of the following reactions does not form gaseous product ?

$\begin {array} {1 1} (a)\;PbO_2+H_2O_2\; \to & \quad (b)\;Acidified \;KMnO_4+H_2O_2\; \to \\ (c)\;PbS+H_2O_2\; \to & \quad (d)\;Cl_2+H_2O_2 \;\to \end {array}$