Question

Tarnished silver contains Ag₂S.Can this tarnish be removed by placing the tarnish silver ware in an aluminium pan containing an inert electrolyte?(Given standard electrode ppotential for Ag₂S= -0.71V AND Al³⁺=1.66v)

Answer 1

Following reaction takes place in this case:

3 Ag₂S + 2 Al ------> 6 Ag + Al₂S₃

Thus in this case aluminum displaces silver from Ag₂S as reduction potential of Al³⁺ is -1.66 and not +1.66 so a metal with the negative reduction electrode potential can displace the metal of positive reduction electrode potential ( Ag = +0.80).

Hence tarnish can be removed by placing the tarnish silver ware in an aluminum pan containing.