Question

Which of the following gas is primarily responsible for the characteristic pungent smell of rotten eggs?

• A. Sulfur Dioxide
• B. Hydrogen Sulfide
• C. Ammonia
• D. Carbon Monoxide

Hint:

Rotten egg smell = Hydrogen Sulfide (H$_2$S) Burning match smell = Sulfur Dioxide (SO$_2$) No smell = Carbon Monoxide (CO)

Answer 1

The Correct Option is B

Step 1: Understand the clue.
We need the gas that smells like rotten eggs.

Step 2: Identify it.
Hydrogen sulfide ($H_2S$) is a colourless, toxic gas with the typical rotten-egg smell.

Step 3: Where it forms.
It comes from the decay of sulfur-containing matter, so it is found in sewage, swamps and volcanic gases.

Step 4: Rule out others.
Sulfur dioxide smells like a burning match. Ammonia has a sharp cleaning-product smell. Carbon monoxide is odourless.

Step 5: Conclude.
The rotten-egg gas is hydrogen sulfide.

Answer: Hydrogen Sulfide