6.3.3: Disposing of Polymers

Question 1

Why are polyalkenes chemically inert

Answer 1

bonds between repeating units are non-polar so they aren’t susceptible to attack from nucleophiles

Question 2

Chemically inert polymers are

Answer 2

non-biodegradable,

can’t be hydrolysed and won’t break down naturally

Question 3

Which polymers are biodegradable

and why?

Answer 3

• condensation polymers
• polar bonds between repeating units, so are susceptible to nucleophilic attack so can be hydrolysed
• slow process

Question 4

Three methods of polymer disposal

Answer 4

burying waste plastic
burning waste plastic
recycling plastics

Question 5

Landfill advantages

Answer 5

relatively cheap and easy method

Question 6

Landfill disadvantages

3

Answer 6

1. requires areas of land
2. as waste decomposes, it releases methane
3. as waste decomposes, it releases toxins which can be washed away and contaminate water supplies

Question 7

Burning waste advantage

Answer 7

heat from burning used to generate electricity

Question 8

Burning waste disadvantages

2

Answer 8

1. process must be carefully controlled to reduce toxic gases
2. waste gases contribute towards greenhouse effect

Question 9

Burning waste

how are toxic gases neutralised

Answer 9

waste gases from combustion passed through scrubbers which neutralises gases such as HCl by reacting them with a base

Question 10

Recycling plastics disadvantages

4

Answer 10

• technically difficult process
• more expensive than burning or landfill
• often can’t remake the original plastic, have to make something else
• plastic can be easily contaminated during the process

Question 11

Recycling plastics advantages

4

Answer 11

• reduces amount of waste going to landfill
• saves raw materials, important as oil is non-renewable
• cheaper than making new plastic from scratch
• produces less CO2 emissions than burning plastic