Chapter 19, Problem 61QP

Tarnished silver contains ${\text{Ag}}_{\text{2}}\text{S}$. The tarnish can be removed by placing silverware in an aluminum pan containing an inert electrolyte solution, such as NaCl. Explain the electrochemical principle for this procedure. [The standard reduction potential for the half-cell reaction ${\text{Ag}}_{\text{2}}\text{S(}s\text{)+2}e\underset{}{\to }2\text{Ag}(s)+{\text{S}}^{2-}(aq)\text{ is -0}\text{.71 V}\text{.]}$