Chapter 22, Problem 8STP

Interpretation Introduction

Interpretation:

The correct statement for X electrode needs to be determined.

Concept introduction:

In a half cell, if reduction takes place thus, electrons are gained by an element and its oxidation number decreases. Also, during oxidation electrons are lost. The oxidation takes place at anode and reduction takes place at cathode.

Answer to Problem 8STP

Correct Answer: Option (a) is correct.

Explanation of Solution

Reason for correct options:

Metal M is immersed in 1 M solution of $X^{+}$ ions. A positive reduction potential is reads on a voltmeter when half cell is connected to hydrogen electrode. Here, hydrogen electrode is reference electrode; if positive reduction potential is reads on the voltmeter thus reduction of metal takes place. Reduction takes place electrons are accepted thus, option (a) is correct.

Conclusion

Reason for incorrect options:

Since, the reduction potential is positive thus, it undergoes reduction not oxidation. After reduction, $X^{+}$ ions changes to X thus, $X^{+}$ ions are removed from the solution. Oxidation takes place at anode and reduction takes place at cathode thus, options (b), (c) and (d) are incorrect.