Ethyl mercaptan (also called ethanethiol), commonly used as an odorant in LPG, belongs to which class of compounds?

Introduction:
Ethyl mercaptan (ethanethiol) is widely recognized as the strong-smelling odorant added to otherwise odorless LPG to enable leak detection. Correctly classifying it reinforces understanding of sulfur chemistry in fuels and the need for handling precautions due to odor and corrosion potential.

Given Data / Assumptions:

• Chemical: CH3–CH2–SH (ethanethiol).
• Use: odorant in LPG at low concentrations.
• We must identify the chemical family.

Concept / Approach:
“Mercaptan” is an older term for thiol compounds, which are sulfur-containing organics with the –SH functional group. Therefore, ethyl mercaptan is a sulfur compound. It is not a nitrogen compound (no –NH or amine functionality) nor an oxygenate (no –OH or ether). It is also not a halogenated hydrocarbon.

Step-by-Step Solution:
1) Identify functional group: –SH indicates a thiol (mercaptan).2) Map thiols to “sulfur compounds.”3) Select “Sulphur compound.”

Verification / Alternative check:
Material safety data and fuel standards classify ethanethiol among sulfur odorants; similar odorants include tert-butyl mercaptan.

Why Other Options Are Wrong:
Nitrogen compound: Would require amine/amide functionality.Oxygenate: Implies alcohols/ethers, not present here.None/halogenated: Do not match the –SH thiol identity.

Common Pitfalls:
Confusing “mercaptan” terminology; despite older naming, it unequivocally denotes sulfur-containing thiols.

Final Answer:
Sulphur compound