Chapter 11

Question 1

State the main non-renewable material used in the production of plastic.

Answer 1

Crude oil

Question 2

Describe the trends evident in the usage of plastics since 1950’s.

Answer 2

The volume of plastic that societies have become accustomed to using in recent decades is hugely problematic. It is very clear how the cumulative plastic use across the globe has increased along exponentially since WW2.

Question 3

Which type of plastic use is the largest?

Answer 3

Food and drink packaging.

Question 4

State a way in which NI has put legislation in place to reduce plastic use. Has this been effective?

Answer 4

In 2013 a 5p levy on single use carrier bags was introduced in NI. Since its introduction in England in 2015 the seven largest shopping retailers announced an 86% reduction in the sale of single use carrier bags. This simply yet incredibly effective piece of legislation has had a huge influence in reducing plastic usage.

Question 5

State the number of tonnes of plastic produced globally in 1950 and compare this to the number of tones produced in 2015.

Answer 5

In 1950 there was 0 tonnes of plastic being produced globally, however, 65 years later in 2015 there is over 350 million tonnes of plastic being produced worldwide.

Question 6

State the two largest uses of crude oil.

Answer 6

1. Transportation.
2. Energy sectors.

Question 7

After these two uses what is the biggest use of crude oil?

Answer 7

Production of plastics

Question 8

Explain the process of evaporation

Answer 8

As energy is added to a liquid taking it up to its boiling pint and then beyond the boiling point, the energy is added to the molecules. When sufficient energy is added the bonds between molecules are broken. The liquid undergoes a change of state from a liquid to a gas.

Question 9

Explain the process of condensation.

Answer 9

A gas has energy removed when the temperature is reduced to the boiling point. When energy contributes to be removed the materials temperature reminds at the billing pint the molecules continue to lose energy and bonds are made between them. The material is changing state from a gas to a liquid at the same temperature. As the material continues to lose energy it is in the liquid state and its temperature falls.

Question 10

What does crude oil extracted from the ground consist of?

Answer 10

Crude oil extracted from the ground consists of molecules of hydrogen and carbon. The molecules are commonly referred to as hydrocarbons.

Question 11

Explain the relationship between hydrocarbon length and its physical properties.

Answer 11

Short hydrocarbons: are more volatile resuming in them making better fuels.
Longer hydrocarbons: are less volatile resulting in poorer fuels. Other uses are generally derived from these longer hydrocarbons.

Question 12

What is the problem associated with crude oil derived plastic with reference to its degradation?

Answer 12

The bonds between the hydrocarbon molecules are very strong. Naturally occurring organisms that break waste products down in the environment have only been subjected to plastics for a few decades. They are unable to break them down effectively. As such, plastic wastes ending hp in landfill or in the Earth’s oceans, can take hundreds even thousands of years to break down fully.

Question 13

A lot of plastic accumulates in landfill. Where else has plastic accumulation been a major problem in recent years? State some of the adverse effects of this.

Answer 13

Plastics have become a major problem in our oceans in recent years. The plastics are making their way into water courses and are being concentrated on beaches and in localised regions of the oceans, depending convection currents.

Question 14

Comment on the relative percentage of plait recycled by the EU and the USA. Which region is better prepared for the future in your opinion? Explain tour answer.

Answer 14

I believe that the EU is better prepared for the future. This is due to the fact that in the USA it is estimated that the ‘Great Pacific Garbage Patch’ is some 80,000 tonnes. The area is believed to be approximately twice the size of Texas in the USA. However, it is evident that the EU is takin positive steps to significantly increase drastically the amount of plastic waste that is recycled, so that it reached approximately 40% in 2015.

Question 15

Q4. Describe the process of incineration of plastic. Are there any potential benefits to this process?

Answer 15

The incineration of plastic may seem like a viable solution. Less waste is sent to landfill and indeed energy can be extracted from the pro scenes, which may be used to produce electricity or heat water for homes.

Question 16

Q5. Is it advisable to incinerate plastic waste? Explain your answer.

Answer 16

No it is not. This is due to the fact that the incineration of plastic can release toxic gases.

Question 17

Q6. State three toxic gases given off when plastic is incinerated.

Answer 17

1. Carbon monoxide.
2. Hydrogen cyanide.
3. Hydrochloride acid.

Question 18

Stage one application for photodegradable plastic and describe its impact on crops or the environment.

Answer 18

Plastic Films:
Weeds can be considerably reduced, which improves growth conditions for the crops planted. Soil temperature can be increased, which promotes growths particularly in cooler periods of the year and in poor soil types. The plastic mulch film prevents excessive water loss from the soil and nutrients through evaporation when in direct sunlight. This is vital in regions that require water irrigations.

Question 19

Explain what is meant by the term ‘biodegradable plastics’.

Answer 19

Plastic that can be broken down by microorganisms, bacteria or other biological means.

Question 20

Describe two applications of biodegradable plastics.

Answer 20

Food packaging:
Biodegradable plastic may be utilities in single use plastic applications such as carrier bags, food packaging and plastic bottles. As this plastic is biodegradable, when it arrives at landfill it will degrade nitrogen rapidly under the action of microorganisms and bacteria in the landfill environment.

Question 21

Many plastics are photodegradable. Describe how a plastic can be modified during the manufacturing process to make it photodegradable.

Answer 21

During the manufacturing process different chemicals can be added to the long chain hydrocarbon molecules. These chemicals are selected as they can be easily broken down when subjected to UV light. When broken down they attack the hydrocarbon polymer na break it down.

Question 22

Plastics can be manufactured to be compostable. Describe one agricultural use of compostable plastics.

Answer 22

If plastics are made from biomass, they are compostable and will degrade naturally. These bioplastics can be made from corn starch and are compostable and biodegradable as they will degrade into small pieces over time.

Question 23

Describe how bio derived polyethylene (BPE) a recyclable plastic (chemical equation not required .

Answer 23

In the PE monomer ethylene is formed by cracking of a fraction of crude oil, from the fractional distillation process. The cracking process further breaks down hydrocarbons into smaller lengths. But in the production ofBPE the ethylene is not derived from crude oil. Biomass crops are used as the raw materials. These crops can be broken down by bacteria, yeasts and other microorganisms though the process of fermentation. This process produces ethanol which can be converted ethylene.

Question 24

Two advantages of biodegradable plastics are:

They can be manufactured using renewable materials
They reduce environmental pollution.

Describe how each of the points above can be considered as an advantage.

Answer 24

If they are able to be manufactured using renewable materials this will mean that there will be less carbon emissions produced during the manufacturing process.
There will be significantly less litter on the gourd and in nature due to the fact that the plastics are biodegradable.