Chapter 21, Problem 9STP

Interpretation Introduction

Interpretation: The result of placing a clean strip of aluminum in a solution of copper (II) sulfate needs to be explained.

Concept Introduction: If a metal loses electron/s, oxidation takes place. If the activity series of metals is examined taking hydrogen as a reference, the metals above hydrogen can easily get oxidized and metals below hydrogen can easily get reduced (as they have more reduction potential value).

Explanation of Solution

On moving top to bottom in the activity series, the reduction electrode potential increases thus, metals can easily get reduced.

On comparing copper and aluminum, copper is placed below aluminum thus, it has more reduction electrode potential and it more easily gets reduced and oxidation of aluminum takes place.

Thus, if the aluminum strip is placed in a solution of copper (II) sulfate, oxidation of Al takes place and reduction of Cu takes place. Here, Al replaces Cu from its solution to form aluminum sulfate and copper solid.