Alkenes are important industrial chemicals, particularly as raw materials for the manufacture of polymers. Ethene can be used to make poly(ethene). Ethene is used to make chloroethene, which is then used to make poly(chloroethene), and ethene is also used to make tetrafluoroethene, which is used to make poly(tetrafluoroethene).

a. Use displayed formulae to write an equation for the formation of poly(chloroethene) from chloroethene.

b. Why do waste (used) poly(alkene)s cause problems in a landfill site?

c. Burning halogenated polymers such as PVC can release toxic waste products, such as HCl, into the environment.

Explain how this can be minimised.