The first three elements in Group IV are carbon, silicon, germanium. The element germanium has a diamond-type structure. Describe the structure of germanium. A diagram is acceptable.

The first three elements in Group IV are carbon, silicon, germanium. Unlike diamond, graphite is soft and is a good conductor of electricity.

(i) Explain why graphite has these properties.

Zinc is extracted from zinc blende, $\mathrm{ZnS}$.  Zinc blende is heated in air to give zinc oxide and sulphur dioxide. Most of the sulfur dioxide is used to make sulfur trioxide. This is used to manufacture sulfuric acid. Some of the acid is used in the plant, but most of it is used to make fertilisers.

(i) Give another use of sulfur dioxide.

Zinc blende is heated in air to give zinc oxide and sulphur dioxide. Most of the sulphur dioxide is used to make sulphur trioxide. This is used to manufacture sulphuric acid. Some of the acids are used in the plant, but most of them are used to make fertilizers.

(ii) Describe how sulphur dioxide is converted into sulphur trioxide.

Some of the zinc oxide was mixed with an excess of carbon and heated to $1000 °\mathrm{C}$. Zinc distils out of the furnace.

$$\begin{gathered} 2\mathrm{ZnO}+\mathrm{C}\stackrel{}{\rightleftharpoons } 2\mathrm{Zn}+{\mathrm{CO}}_2 \\ \mathrm{C}+{\mathrm{O}}_2\to 2\mathrm{CO} \end{gathered}$$

(i) Name the two changes of state involved in the process of distillations.