Question

Ultrapure germanium, like silicon, is used in semiconductors. Germanium of "ordinary" purity is prepared by the high-temperature reduction of \(\mathrm{GeO}_{2}\) with carbon. The Ge is converted to \(\mathrm{GeCl}_{4}\) by treatment with \(\mathrm{Cl}_{2}\) and then purified by distillation; \(\mathrm{GeCl}_{4}\) is then hydrolyzed in water to \(\mathrm{GeO}_{2}\) and reduced to the elemental form with \(\mathrm{H}_{2}\). The element is then zone refined. Write a balanced chemical equation for each of the chemical transformations in the course of forming ultrapure Ge from \(\mathrm{GeO}_{2}\).

Short answer

1. GeO₂ (s) + C (s) -> Ge (s) + CO₂ (g) 2. Ge (s) + 4Cl₂ (g) -> GeCl₄ (g) 3. (No chemical equation for distillation) 4. GeCl₄ (g) + 2H₂O (l) -> GeO₂ (s) + 4HCl (aq) 5. GeO₂ (s) + 2H₂ (g) -> Ge (s) + 2H₂O (g)

Step-by-step solution

1. Reduction of GeO₂ with carbon

GeO₂ (s) + C (s) -> Ge (s) + CO₂ (g)

2. Conversion of Ge to GeCl₄ by treatment with Cl₂

Ge (s) + 4Cl₂ (g) -> GeCl₄ (g)

3. Purification of GeCl₄ by distillation

No chemical reaction occurs during distillation. The purpose of this step is to separate GeCl₄ from any impurities.

4. Hydrolysis of GeCl₄ in water to form GeO₂

GeCl₄ (g) + 2H₂O (l) -> GeO₂ (s) + 4HCl (aq)

5. Reduction of GeO₂ to elemental Ge with H₂

GeO₂ (s) + 2H₂ (g) -> Ge (s) + 2H₂O (g) These are the balanced chemical equations for the series of reactions involved in the formation of ultrapure germanium from germanium dioxide.