Which of the following is known as laughing gas?

Question

UnlockIAS · Accepted Answer

Correct — C, Nitrous Oxide. Nitrous oxide (N2O) is popularly called 'laughing gas' because inhaling it can produce euphoria and fits of laughter; it is used as a mild anaesthetic and analgesic in dentistry and surgery. The nickname dates to Humphry Davy's early-1800s experiments. So the laughing gas is nitrous oxide.

Why the other options are wrong — (a) Chlorofluorocarbons (CFCs) are refrigerant/aerosol gases infamous for depleting the ozone layer — not an anaesthetic and not called laughing gas.  (b) Ammonia (NH3) is a sharp, pungent, alkaline gas used in fertilizers and refrigeration; it is irritating to inhale, not a euphoria-inducing laughing gas.  (d) Carbon monoxide (CO) is a colourless, odourless but highly poisonous gas that binds haemoglobin and can be lethal — the opposite of a mild anaesthetic.

Concept: Several gases carry common 'trivia' names. Nitrous oxide (N2O) is 'laughing gas', valued as a mild anaesthetic/analgesic. It is a colourless gas with a faintly sweet odour and is also a greenhouse gas. The distractors here are all gases with very different, well-known identities.

State PCS 2023 Q100 — Science & Technology PYQ with Answer

State PCS 2023 Q100 — Science & Technology PYQ with Answer