Chapter 20, Problem 77A

Interpretation Introduction

Interpretation:

Write the importance of maintaining pressure in gas electrode cells.

Concept introduction:

The volume and density of a gas alters with changing physical conditions like pressure and temperature.

Answer to Problem 77A

In a cell where gases are involved as reactants or products, the pressure of gas is critical because the concentration of gas at a particular place of cell can change with change in pressure which can affect the measurement of standard potential.

Explanation of Solution

The concentration of a gas depends on its density at a particular space which depends on the volume of gas which in turn depends on the pressure of gas (temperature remaining constant). If the pressure were to be changed during the measurement of potential, the composition of gas will change which will lead to inaccurate measurement of potential.

Conclusion

The pressure of the cell is kept critical so that the concentration of its gaseous components remain the same.