Question

Which among the following is a formula of mustard gas?

• A. $\mathrm{SOCl_2}$
• B. $\mathrm{COCl_2}$
• C. $\mathrm{S(CH_2CH_2Cl)_2}$
• D. $\mathrm{CCl_3NO_2}$

Hint:

Remember that "sulfur mustard" must have a sulfur ($\mathrm{S}$) atom connecting two identical chloroethyl groups ($\mathrm{-CH_2CH_2Cl}$), leading directly to $\mathrm{S(CH_2CH_2Cl)_2}$.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
We are required to identify the correct chemical formula for the notorious chemical warfare agent commonly known as mustard gas.

Step 2: Key Formula or Approach:
Mustard gas, or sulfur mustard, is chemically named bis(2-chloroethyl) sulfide. It is an organosulfur compound with chlorinated alkyl chains linked via a thioether bridge.

Step 3: Detailed Explanation:
Let's analyze the given chemical formulas:

• $\mathrm{SOCl_2}$: Thionyl chloride, a common reagent in organic chemistry for converting alcohols to alkyl chlorides.

• $\mathrm{COCl_2}$: Phosgene, a highly toxic gas used as a chemical weapon, but it is a carbonyl chloride, not mustard gas.

• $\mathrm{S(CH_2CH_2Cl)_2}$: Bis(2-chloroethyl) sulfide. This perfectly represents the structure of sulfur mustard (mustard gas).

• $\mathrm{CCl_3NO_2}$: Trichloronitromethane, commonly known as chloropicrin, which is used as a tear gas or soil fumigant.

Step 4: Final Answer:
The formula of mustard gas is $\mathrm{S(CH_2CH_2Cl)_2}$, which corresponds to option (C).