Chapter 18, Problem 29A

Interpretation Introduction

Interpretation: Salt bridge and its role in galvanic cell needs to be explained.

Concept Introduction: Electric current is produced through a galvanic cell. In this device, chemical energy is transferred to electrical energy via oxidation-reduction reaction. The electrons must travel through an external circuit from the reducing agent to oxidizing agent. Oxidizing agent is separated from the reducing agent.

Answer to Problem 29A

Salt bridge is a U shaped tube used in oxidation-reduction reaction which connects half cells that is oxidation and reduction in galvanic cell. It is necessary in galvanic cell because without it no flow of current occurs in the cell.

Explanation of Solution

In oxidation-reduction reaction, a U shaped tube which allows ion flow but prevents extensive mixing of solutions is called a salt bridge.

In galvanic cell, there is no flow of electrons takes place without the salt bridge that means there is no current. Salt bridge allows flowing ions through it and keeping the overall charge in each compartment zero.

Instead of salt bridge anything which allows ions to flow in both the beaker can be used.

Conclusion

Oxidation reaction is caused by losing electrons and reduction caused by gaining electrons.