Question

# Why do silver articles turn black when kept open for a few days?$(a)$ Name the phenomenon involved$(b)$ Name the black substance formed and give its chemical formula

Hint – In this question use the concept that the traces of hydrogen sulfide which is present in air reacts with silver to form silver sulfide that is $A{g_2}S$, it is black in color. Use this concept to get the answer of this problem statement.
$\Rightarrow 2Ag\left( {{\text{silver}}} \right) + {H_2}S \to A{g_2}S + {H_2}$
$\left( i \right)$ So the phenomenon is called corrosion.
$\left( {ii} \right)$ And the substance which is formed is silver sulfide (Ag2S) which is black in nature.
Note – A very interesting aspect of ${H_2}S$, is that the effect of it to high exposure greater than ( 100 ppm) can be dangerous and life-threatening. Effects include shock, convulsions, inability to breathe, rapid unconsciousness, coma or even to death.