Chapter 18, Problem 28A

Interpretation Introduction

Interpretation: The set up of oxidation-reduction in a galvanic cell needs to be explained.

Concept Introduction: By transfer of electrons, oxidation-reduction reactions are characterized. The transfer occurs to form ions. Oxidation reaction is caused by losing electrons and reduction caused by gaining electrons.

Answer to Problem 28A

Electric current is produced through a galvanic cell. In this device, chemical energy is transferred to electrical energy via oxidation-reduction reaction.

Explanation of Solution

From an oxidation-reduction reaction, a galvanic cell uses energy to produce an electric current. Electrons are transferred quickly and collide with each other if oxidizing and reducing agent are in contact with each other.

The electrons must travel via external circuit from the reducing agent to oxidizing agent. Oxidizing agent is separated from the reducing agent. Salt bridge is used to avoid the accumulation of charges in the beakers. The below figure represents a galvanic cell:

Reducing agent releases electrons, so is oxidized and oxidizing agent gains electrons and reduced in the other electrode.

Conclusion

An oxidizing agent gains electrons and a reducing agent lose electrons in a redox reaction.