Chapter 21 Polymerization

Question 1

Addition polymerisation

Answer 1

is one of the most important addition reactions of alkenes which form the basis of the plastic industry

• Addition polymerisation is the reaction in which many monomers containing at least one C-C double bond form long chains of polymers as the only product
• Just like in other addition reactions of alkenes, the π-bond in each C-C bond breaks and then the monomers link together to form new C-C single bonds

Question 2

A polymer

Answer 2

• is a long-chain molecule that is made up of many repeating units
• The small, reactive molecules that react together to form the polymer are called monomers

Question 3

A repeat unit

Answer 3

is the smallest group of atoms that when connected one after the other make up the polymer chain

-It is represented by square brackets in the displayed and general formula

Question 4

Disposal of Polymers

Answer 4

• Though poly(alkenes)s are extremely important in everyday such as their use as plastics, the disposal of these polymers is problematic
• Poly(alkenes) are very large alkane molecules which are unreactive and therefore do not undergo any chemical reactions; they are resistant to chemical attack
• Due to their unreactivity, polymers are non-biodegradable and take up to hundreds of years to decompose when dumped in landfill sites
• Throwing away poly(alkenes) therefore cause the long-term pollution of the environment
• Burning the polymers results in harmful combustion products which again cause the pollution of the environment

Question 5

The disposal of polymers is a challenge due to their

Answer 5

unreactivity, their non-biodegradability, and the formation of harmful combustion products when burnt.