Question

What is the smell of hydrogen sulphide at a concentration of 200 ppm?

• A. Pleasant odour
• B. Rotten egg odour
• C. No smell
• D. Rotten fish smell

Answer 1

Answer: (C)

No smell

At higher concentrations, hydrogen sulfide rapidly deadens the sense of smell which means the ability to sense the smell of anything will be no more at such high temperature. For most people, this occurs at approximately $150ppm$. The gas has a characteristic rotten egg odour at low concentrations. About half of the population can smell it at concentrations as low as 8 parts per billion ($ppb$) in the air.

Hence, the correct option is C.