When a mixture of  ${\text{SO}}_{\text{2}}{\text{and Cl}}_{\text{2}}$  gases are passed over cooled activated charcoal  ${\text{SO}}_{\text{2}}{\text{Cl}}_{\text{2}}$  is formed.

Formation of  ${\text{SO}}_{\text{2}}{\text{Cl}}_{\text{2}}$  is a redox reaction.

When  ${\text{SO}}_{\text{2}}{\text{Cl}}_{\text{2}}$  is dissolved in water two different acids will be formed one gives ppt with  ${\text{BaCl}}_{\text{2}}$  and the filtrate give white ppt  $\text{Pb}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}$  .

${\text{SO}}_{\text{2}}{\text{Cl}}_{\text{2}}$  have tetrahedral structure in which sulphur is involved in  ${\text{sp}}^3{\mathrm{d}}^2$  hybridization.

Formation of  ${\text{SO}}_{\text{2}}{\text{Cl}}_{\text{2}}$  is an addition (Oxad) reaction.