Name two poisonous gases which can be prepared from chlorine gas.

Explanation

Two poisonous gases which can be prepared from `Cl_(2)` are (i) phosgene (ii) mustard gas. These are prepared as follows :
(i) `CO + Cl_(2) overset("hv, charcoal")rarr underset("Phosgene")(COCl_(2))`
(ii) `Cl_(2)` is passed through boiling S, when `S_(2)Cl_(2)` is formed. This when reacted with ethene gives mustard gas.