C1- Products from Oil

Question 1

How can cracking be done?

Answer 1

In industrial cracking, the hydrocarbon is heated until it vaporises and then it’s passed over a hot catalyst (e.g: aluminium oxide catalyst).

Question 2

How can presence of alkenes be tested?

Answer 2

Bromine water turns from orange to colourless when it reacts with alkenes.

Question 3

Give three ways in which alkenes are different from alkanes.

Answer 3

1. Alkanes are saturated hydrocarbons, alkenes are unsaturated.
2. Alkenes have a double carbon bond, making them more reactive than alkanes.
3. Alkenes contain fewer hydrogen atoms than alkanes.

Question 4

What is a polymer?

Answer 4

Polymers are large molecules formed from many small molecules (monomers) joined together. These monomers are alkenes.

Plastics are made of polymers.

Question 5

What happens in the polymerisation process?

Answer 5

In the polymerisation reaction the double bond in each alkene molecule becomes a single bond and thousands of the alkene molecules joins together in long chains.

The double bond is made into a single bond with heat and under pressure in the presence of a catalyst.

Question 6

What is poly(e)thene and its uses?

Answer 6

Poly(e)thene is made from polymerising ethene molecules.

Polythene is cheap and strong.

It is used to make plastic bags and bottles.

Question 7

What is polypropene and its uses?

Answer 7

Polypropene is made from polymerising propene molecules.

Polypropene is strong and has high elasticity. It is used for crates and ropes.

Question 8

Define biodegradable.

Answer 8

Undergoes decomposition by micro-organisms.

Question 9

Many polymers are not biodegradable.

Why is this an issue?

Answer 9

Unless disposed of properly, this causes unsightly rubbish and can harm wildlife.

Even when disposed of it takes up lots of valuable space in landfill sites.

Question 10

How can cornstarch be used to help withdraw problems of disposal of plastic waste?

Answer 10

Making plastics with cornstarch mixed in helps micro-organisms to break down plastic into very small pieces that can be mixed with soil or compost.

We can make biodegradable plastics from plant material such as cornstarch.

Question 11

Give an advantage and disadvantage to disposing of polymers by:

1. Incinerating.
2. Landfill.

Answer 11

1. A- Releases useful energy.
2. D- Produces toxic gases and CO₂.
3. A- Gets it out of the way.
4. D- Does not actually get rid of it.

Question 12

Give an advantage and disadvantage to disposing of polymers by:

1. Recycling.
2. Redesigning.

Answer 12

1. A- Environmentally friendly.
2. D- Costly, can’t recycle all polymers.
3. A- Would solve all problems.
4. D- Costly.

Question 13

How can ethanol be produced in batch process fermentation?

Give the word and symbol equation.

Answer 13

Glucose➡️(add yeast + water at 37^oC)➡️Ethanol + CO₂

C₆H₁₂O₆➡️ 2C₂H₅OH + 2CO₂

Question 14

How can ethanol be made using ethene?

Answer 14

Hydration of ethene.

Ethene is reacted with steam at a high temperature in the presence of a catalyst.

Question 15

Give advantages and disadvantages of using ethanol as a fuel.

Answer 15

A- Renewable energy source.

A- Only produces CO₂ and water.

A- Carbon neutral.

D- Releases less energy than burning petrol.

D- Diverts food resourced which makes food more expensive.

D- Takes a lot of farmland which makes farmland expensive.

Question 16

What is cracking?

Answer 16

Cracking is the process of breaking down large hydrocarbons into smaller molecules.

Question 17

Some polymers are described as smart polymers.

Suggest one property of a smart polymer that is different to that of an ordinary polymer.

Answer 17

Shape memory alloy.

Smart polymer.