EQ's

Question 1

What is a mixture?

[1 mark]

Answer 1

A mixture is when there two or more elements or compounds which are not chemically bonded together

Question 2

Napatha and diesel are hydrocarbons

Napatha has a lower boiling point than diesel

Explain why

[2 marks]

Answer 2

Napatha contains shorter chains of hydrocarbon molecules

So the intermolecular forces between molecules are weaker, and so less energy is required to break the bonds

Question 3

A hydrocarbon was combusted and a product of this combustion was carbon monoxide

Suggest a reason why this product was formed

[1 mark]

Answer 3

The hydrocarbon was not fully burned due to an insufficient supply of oxygen, this is incomplete combustion

Question 4

Which one of the following is a use for alkenes?

1. To make roads
2. As fuel
3. For medecine
4. To make plastics

Answer 4

4. To make plastics

Question 5

The reaction between water (steam) and ethene produces ethanol in the presence of a phosphoric acid catalyst.

This is a reversible reaction

Explain how the yield of ethanol can be increased in this hydration reaction

[2 marks]

Answer 5

The excess ethene and water should be recycled and passed through the phosphoric acid catalyst again

Question 6

Oxygen is needed to burn fuels.
Name the source of the oxygen needed to burn fuels.

Answer 6

Air

Question 7

Explain how alkenes are produced using cracking

[3 marks]

Answer 7

1. An alkane is cracked in conditions of high temperature in the presence of steam/a catalyst
2. Large molecules split into smaller molecules
3. A mixture of short chained alkanes and alkenes are produced

Question 8

What environmental impact is caused by the pollutant of oxides of nitrogen?

Answer 8

Acid rain

Question 9

In industry, how is the percentage of unsaturated fat in an oil reduced to turn it into a spreadable solid (saturated fat)?

[3 marks]

Answer 9

1. Hydrogen is reacted with an alkene
2. in the presence of a nickel catalyst at
3. 150 degrees celcius to produce a saturated, spreadable solid

bc hydrogen + unsaturated alkene = saturated (alkane) fat

Question 10

What is the difference, in terms of the molecules, between saturated and unsaturated fats?

Answer 10

1. In unstaturated fats there is a double bond
2. between carbon atoms

Question 11

Suggest why the boiling points of hydrocarbons increase as the number of carbon atoms increases.

[3 marks]

Answer 11

The number of intermolecular forces

Increases

And so more heat energy is required to overcome the forces

Question 12

Give three uses of alcohols

Answer 12

Solvents

Alcoholic drinks

Fuels

Question 13

A beaker contains a liquid

The liquid is either analcohol or a carboxylic acid.

Describe a test and the result of the test to see which hydrocarbon is inside the beaker

Answer 13

Add 5 drops of an acid-base indicator

The alcohol will not change colour but the carboxylic acid will change colour to orange

Question 14

Name three uses of esters

Answer 14

Food flavourings

Perfume

Fuels

Question 15

Polystyrene is a polymer

Disposal of objects containing polystyrene can cause environmental damage.

Explain why

Answer 15

Polystyrene does not decompose

It will take up space when thrown into landfill

Burning it will cause pollution

Question 16

Compare the polymerisation reaction used to produce poly(ethene) with the polymerisation reaction used to produce a polyester.

[4 marks]

Answer 16

The polymerisation to produce poly(ethene) is additional polymerisation, whereas to produce polyester its condensation polymerisation

Poly(ethene) is produced from one monomer, Polyester is produced from two different monomers

Poly(ethene) is produced from ethene, Polyester is produced from carboxyllic acid and alcohols

Additional polymerisation, only produces poly(ethene), Condensation polymerisation produces polyester AND water

Question 17

Which part of the structure of ethenes allow them to be polymerised?

[1 mark]

Answer 17

Their carbon to carbon double bond

Question 18

What is the name given to a useful product like methylated spirit?

[1 mark]

Answer 18

Formulation

Question 19

Suggest why an alcohol may be given an unpleasant smell or an odd colour

[1 mark]

Answer 19

To deter people from drinking it

Question 20

Describe how ethanol is produced from sugar solution

Give the name of this process

[3 marks]

Answer 20

Fermentation

Add yeast to the sugar solution

In warm (30 degrees Celcius) and anaerobic conditions

Question 21

Name the gas produced whensodium is added to ethanol

[1 mark]

Answer 21

Hydrogen gas

Question 22

Carboxylic acids react with alcohols in the presence of an [blank] catalyst

fill in the blank

Answer 22

Carboxylic acids react with alcohols in the presence of an acid catalyst

Question 23

Explain why increasing the use of biofuels may cause food shortages

Answer 23

If fertile land is being used to grow crops for fuel

Then there will be less fertile land available to grow crops for food

Question 24

Explain why burning biofuels contributes less to climate change than burning fossil fuels

[2 marks]

Answer 24

The plants for biofuels take in carbon dioxide while growing during photosynthesis

So the carbon dioxide released is the one that was previously taken in

Question 25

What type of reaction produces ethanoic acid from ethanol?

Answer 25

Oxidation reaction

Question 26

Explain why the solution of ethanoic acid has a higher pH than the solution of hydrochloric acid

[2 marks]

Answer 26

Ethanoic acid is a weaker acid because

it has a lower concentration of H⁺ ions and so is only partially ionising

Question 27

What type of chemical is used as a catalyst in the reaction that produces ethyl ethanoate?

[1 mark]

Answer 27

Acid

Question 28

What does volatile mean?

Answer 28

Evaporates quickly

Question 29

Describe the test to test for an alkene

[2 marks]

Answer 29

Add bromine water

If an alkene is present it will change colour from orange to colourless