Q b)
Some plastics, formed by polymerisation, are non-biodegradable. Describe two
pollution problems that are caused by non-biodegradable plastics.
Answer:
1. They accumulate in the environment as litter and clog drains, causing
flooding and pollution.
2. They harm wildlife when animals eat them or get entangled in them,
leading to injury or death.
Q c)
The polymer known as PVA is used in paints and adhesives. Its structural
formula is shown. Deduce the structural formula of its monomer.
Polymer segment: –CH₂–CH(–OCOCH₃)–
Monomer = CH₂=CH–OCOCH₃ (vinyl acetate).
Q 3 a)
Polymer structure given with repeating unit –CH(CH₃)–CH(CH₃)–. Draw the
structural formula of its monomer.
Polymer: –[–CH–CH–]– with each C having –CH₃ side group.
Monomer = CH₂=C(CH₃)₂ (2-methylpropene).
Q 3 II)
State three problems caused by the disposal of non-biodegradable polymers.
Answer:
1. They do not decompose and accumulate in landfills.
2. They release toxic gases if burnt.
3. They pollute soil and water, harming animals and plants.
Burning synthetic polymers produces toxic gases such as carbon monoxide or hydrogen
chloride. These gases cause air pollution and can lead to health problems like breathing
difficulties in humans and animals.
Uses- done in ppt
d- propene
CH2=CH(CH3)
ALDEHYDE/KETONE
Q 3 III)
Storage tanks for cold water are now made from polymers. Suggest two other
advantages (apart from cost).
Answer:
1. They are lightweight and easy to transport/handle.
2. They do not rust or corrode like metal tanks.
Q 4 a I)
Major use of PVC is insulation of electric cables. PVC is a poor conductor of
electricity. Suggest another property which makes it suitable.
Answer: It is flexible and resistant to heat/chemicals.
Q 4 a II)
One way of disposing waste PVC is burning. Suggest two poisonous gases
formed.
Answer:
1. Hydrogen chloride (HCl) gas
2. Carbon monoxide (CO)
Q 4 b I)
Deduce the structural formula of the monomer from polymer (–CH₂–
CH(CH₃)–).
Monomer = CH₂=CH–CH₃ (propene).
Q 4 b II)
Deduce structural formula of poly(phenylethene) from its monomer (styrene).
Monomer: C₆H₅–CH=CH₂
Polymer: –[–CH₂–CH(C₆H₅)–]–ₙ
Structural formula of monomer
CH2=CH(CH3)bold cap C bold cap H sub 2 equals bold cap C bold cap H open paren bold
𝐂𝐇𝟐=𝐂𝐇(𝐂𝐇𝟑)
cap C bold cap H sub 3 close paren
Q 5 a)
Two methods for disposal of waste plastics: burning and recycling.
Burning:
o Advantage: reduces waste volume and can produce energy.
o Disadvantage: releases toxic gases and air pollution.
Recycling:
o Advantage: conserves resources, reduces pollution.
o Disadvantage: sorting and processing are costly and time-
consuming.
