Chapter 18, Problem 41A

Interpretation Introduction

Interpretation: The reason for the aluminum metal to be produced by electrolysis but not by simpler chemical reduction needs to be explained.

Concept Introduction: Electrolysis is the breakdown of compound’s chemical bonds to create elemental substances. The method involves passing of electrical current through the electrolyte to be degraded at different voltage between two electrodes. The electrolytes consist of cations and anions.

Answer to Problem 41A

Current is passed through a molten mixture of ${\text{Al}}_{\text{2}}{\text{O}}_{\text{3}}$ and ${\text{Na}}_{\text{3}}{\text{AlF}}_{\text{6}}$ , in Hall process to extract aluminum from its bauxite ore. Al is more reactive so, it cannot be produced by simpler chemical method.

Explanation of Solution

Aluminum is the most abundant elements on the Earth as it is very reactive. In nature it is found as bauxite ore. By passing current through a molten mixture of ${\text{Al}}_{\text{2}}{\text{O}}_{\text{3}}$ and ${\text{Na}}_{\text{3}}{\text{AlF}}_{\text{6}}$ , aluminum is produced. The Electrolysis process has the effect of reducing ${\text{Al}}^{3+}$ ions to neutral Al atoms from the alloy of aluminum.

Simpler chemical reduction is not used to produce Al as it is a most reactive.

Conclusion

In electrolysis, chemical change is produce by forcing a current through a cell.