Question

silver when exposed to air become black due to the formation of

Answer 1

Ag(No3)2. when is exposed to air becomes black due to formation of silver nitrate

Answer 2

Answer: $Ag_2S$

Explanation: Silver when left exposed to atmosphere undergoes oxidation and combines with sulfide ions to form silver sulfide which is black in color.

Oxidation: $2Ag\rightarrow 2Ag^++2e^{-1}$

Reduction: $S+2e^{-1}\rightarrow S^{2-}$

Overall reaction: $2Ag^++S^{2-}\rightarrow Ag_2S$