Question

Name the agent responsible for:
(a) Offensive odour of rotten eggs.
(b) Blackening of an old lead painting.
(c) Blackening of silver coin by atmospheric air.
[3 MARKS]

Answer 1

Each option: 1 Mark

(a) $H_{2}S$ gas
(b) $H_{2}S$ gas
(c) $H_{2}S$ gas, because if air contains some traces of $H_{2}S$, silver gets black stains of $A{g}_{2}S$.