Question

Phosgene is a common name for:
(A) Carbon tetrachloride
(B) Carbonyl dichloride
(C) $C{O}_2$ and $P{H}_3$
(D) Phosphoryl chloride

Answer 1

Hint: Phosgene is an organic compound. It has an electrophilic carbon atom which can easily be attacked by nucleophiles. Its molecular formula is $COC{l}_2$.

Complete answer:
We will get some information about phosgene.
- Phosgene is an organic compound. Its molecular formula is $COC{l}_2$. It contains a carbonyl group. Two chlorine atoms are bonded to the carbonyl carbon. The molecule is planar and its shape is trigonal.
- It is a colourless gas. The smell of phosgene is like freshly cut grass. It is a very poisonous gas and it was used in world war-2 and was responsible for thousands of deaths.
- Phosgene is also called carbonyl dichloride. It is also known as dichloromethanal, dichloromethanone and carbon oxychloride.
- It is produced by the reaction of carbon monoxide with chlorine gas in presence of carbon catalyst.
- Phosgene is useful in the synthesis of isocyanates which may be used to produce polyurethane polymers. It is also useful in the synthesis of polycarbonates. Polycarbonates are the polymers which are used in the manufacture of lenses in eyeglasses.
- Phosgene reacts with water to give carbon dioxide and hydrochloric acid.
- Carbonyl carbon in phosgene is electrophilic and is a good site of attack for nucleophiles.
- Thus, we can conclude that phosgene is also known as carbonyl dichloride.

Therefore, the correct answer of this question is (B).

Note:
Do not get confused between phosphine and phosgene. Phosphine is a gaseous inorganic compound and its molecular formula is $P{H}_3$. Phosgene is an organic compound with molecular formula $COC{l}_2$.