Question

Which of the following is responsible for the tarnishing of silver?

• A. $H_{2}S$
• B. $H_{2}O$
• C. $HCl$
• D. $C{O}_2$

Answer 1

The correct option is A $H_{2}S$

Tarnish is a thin layer of corrosion that occurs on copper, brass, iron, magnesium, neodymium and other related metals. Silver, for instance, requires hydrogen sulphide to tarnish, but over time it can tarnish with oxygen. Silver reacts with sulphur and sulphur compounds in the air give silver sulphide $\left(A{g}_{2}S\right)$ which is black in colour.