Question

Which of the following halogen derivative forms a poisonous phosgene, when come in contact with air and light?

• A. \(\text{CHCl}_3\)
• B. \(\text{PCl}_3\)
• C. \(\text{C}_6\text{H}_5\text{Cl}\)
• D. \(\text{CH}_2\text{Cl}_2\)

Hint:

Chloroform is stored in dark bottles because it forms phosgene.

Answer 1

The Correct Option is A

Step 1: Recall:
Phosgene is $COCl_2$. It comes from oxidation of chloroform.

Step 2: Storage clue:
Chloroform is sold in dark bottles with a little ethanol. That precaution exists because of phosgene formation.

Step 3: Pick:
Option (A).

Final Answer:
The reason for dark bottles of chloroform is phosgene formation. \[ \boxed{A} \]