Question

Silver jewellary turns black on long exposure to air. This is due to the formation of:

• A. $A{g}_{2}O$
• B. $A{g}_{3}N$
• C. $A{g}_{2}O+A{g}_{3}N$
• D. $A{g}_{2}S$

Answer 1

The correct option is D $A{g}_{2}S$

Silver is stable in pure water and air but tarnishes when it is exposed to air or water containing hydrogen sulfide, the latter forming a black layer of silver sulfide which can be cleaned off with dilute $HCl$.

$2Ag+H_{2}S\to \underset{black.}{A{g}_{2}S}+H_2$