Question

Which of the following compounds is formed when chloroform is exposed to air and light?

• A. Phosgene.
• B. Phosphine.
• C. Carbon dioxide
• D. Carbon tetrachloride

Hint:

Chloroform is slowly oxidised by air and light to poisonous phosgene.

Answer 1

The Correct Option is A

Step 1: Identify the reagents:
The reagents are air (oxygen) and light, so this is an oxidation of $\text{CHCl}_3$.

Step 2: Track the atoms:
Two $\text{CHCl}_3$ take one $\text{O}_2$. The carbon gains oxygen to form a C=O group, and H and one Cl leave as HCl, which leaves $\text{COCl}_2$.

Step 3: Pick:
$\text{COCl}_2$ is phosgene, option A.

Final Answer:
Air and light oxidise chloroform to carbonyl chloride, or phosgene. \[ \boxed{\text{(A) }\text{Phosgene}} \]