Question

Which one of the following substances do silver articles react with, that makes the silver articles black ?
1. Sulphur
2. Oxygen
3. Carbon dioxide
4. Phosphorus

Answer 1

Correct Answer - Option 1 : Sulphur

The correct answer is Sulphur.

• The silver article turns black when kept in the air because silver article reacts with sulphur compounds such as hydrogen sulphide (H₂S) present in the air.
• The phenomenon is called corrosion.
• For silver particularly, it is called tarnishing of silver.

• Silver reacts readily with sulfur or hydrogen sulfide (H₂S) to produce silver sulfide (Ag₂S), a dark-colored compound familiar as the tarnish on silver coins and other objects.
• Silver sulfide also forms silver whiskers when silver electrical contacts are used in an atmosphere rich in hydrogen sulfide.
• Silver is found generally in lead ores, copper ores, and cobalt arsenide ores and is also frequently associated with gold in nature.
• Most silver is derived as a by-product from ores that are mined and processed to obtain these other metals.