$\text{CHCl}_3$ is a colourless liquid with a high vapour pressure. Explain what is meant by the term high vapour pressure.
A significant reaction of $\text{CHCl}_3(g)$ is the production of $\text{CHClF}_2(g)$ by means of the reversible reaction: $\text{CHCl}_3(g) + 2\text{HF}(g) \rightleftharpoons \text{CHClF}_2(g) + 2\text{HCl}(g)$ Use the data to work out the enthalpy change of reaction, $\Delta H_r$, for forming $\text{CHClF}_2(g)$ as shown in the equation.
The reaction in (ii) uses a heterogeneous catalyst. Explain fully what is meant by the terms heterogeneous and catalyst.
$\text{CHClF}_2$ was used in place of chlorofluorocarbons (CFCs). $\text{CHClF}_2$ should no longer be used because it was found to contribute to the enhanced greenhouse effect. Give the meaning of the term enhanced greenhouse effect.
Explain how $\text{CHClF}_2(g)$ may contribute to this effect.
Suggest another environmental problem associated with the use of $\text{CHClF}_2$.
$\text{CHClF}_2$ is also used to make the monomer tetrafluoroethene, $\text{C}_2\text{F}_4$. This monomer can be used to make poly(tetrafluoroethene), PTFE. State the type of polymerisation that occurs during the production of PTFE.
Draw the repeat unit of PTFE.
Suggest why PTFE is used as a coating for cooking pans.
Waste disposal can create litter issues. State two other difficulties associated with the disposal of PTFE.