Chapter 19, Problem 19.41QP

Interpretation Introduction

Interpretation:

Electrochemically should explain the removal of silver tarnish by dipping it in an aluminum container with $\text{NaCl}$ solution.

Concept introduction:

Silver reacts with hydrogen sulfide to produce tarnished silver (Ag₂S), which is a black layer formed over silver. The chemical reaction for the tarnish formation was given below.

    $\text{2Ag +}{\text{H}}_2\text{S}\to {\text{Ag}}_{\text{2}}{\text{S+H}}_{\text{2}}$

Generally tarnishing area of metal act as anode and under goes oxidation. Tarnish of the metal can be restored by electrochemical reduction with strong oxidizing agents.