All Saints Secondary Standard Grade Chemistry
Topic 6 Homework– Hydrocarbons
General Level
1. The names of some hydrocarbons are shown.
A / B / Cethene / propene / methane
D / E / F
butane / hexene / pentene
(a) Identify the hydrocarbon which is the first member of the alkene family.
1 mark (KU)
(b) Identify the hydrocarbon with five carbon atoms in each molecule.
1 mark (KU)
(c) Identify the hydrocarbon with a boiling point of 30 °C.
You may wish to use page 6 of the data booklet to help you.
1 mark (PS)
2. Hydrocarbons are compounds containing hydrogen and carbon only.
A / B / CCH4 / C2H4 / C6H14
D / E / F
C5H12 / C3H8 / C4H8
(a) Identify the molecular formula for pentane.
1 mark (KU)
(b) Identify the two molecular formulae which represent alkenes.
1 mark (PS)
(c) Identify the hydrocarbon which has a boiling point of 69°C.
You may wish to use page 6 of the data booklet to help you.
1 mark (PS)
3. Two families of hydrocarbons are alkanes and alkenes.
propane / hexene / pentane
D / E / F
pentene / ethene / propene
(a) Identify the two hydrocarbons which are alkanes.
1 mark (KU)
(b) Identify the two hydrocarbons with three carbon atoms in each molecule.
1 mark (KU)
(c) Identify the hydrocarbon with the highest boiling point.
You may wish to use page 6 of the data booklet.
1 mark (PS)
4. There are many types of chemical reaction.
Identify the chemical reaction represented by this equation.
1 mark (PS)
5. Testing Gases
Identify the test which you would use to distinguish between propane and propene.
1 mark (PS)
6. Many terms are used to describe different chemical reactions.
A / B / Caddition / combustion / cracking
D / E / F
neutralisation / precipitation / distillation
(a) Identify the term which describes this reaction.
1 mark (KU)
(b) Identify the reaction(s) in which oxygen is used up.
1 mark (KU)
7. Hydrocarbon compounds are obtained from crude oil.
butene / propane / hexene
D / E / F
pentane / pentene / propene
(a) Identify the two hydrocarbons which are alkanes.
1 mark (KU)
(b) Identify the hydrocarbon which has the following structural formula.
1 mark (KU)
(c) Identify the hydrocarbon with the highest boiling point.
You may wish to use page 6 of the data booklet to help you.
1 mark (PS)
8. The formulae for some hydrocarbons are shown in the grid.
A / B / CCH4 / C2H4 / C6H14
D / E / F
C5H12 / C4H10 / C4H8
(a) Identify the two hydrocarbons which could be produced when propane (C3H8) is cracked.
1 mark (PS)
(b) Identify the two unsaturated hydrocarbons.
1 mark (PS)
(c) Identify the hydrocarbon with the highest boiling point.
You may wish to use page 6 of the data booklet to help you.
1 mark (PS)
9. The grid below shows some simple experiments.
(a) Identify the experiment which gives water as a product.
1 mark (PS)
(b) Identify the experiment in which an addition reaction takes place.
1 mark (PS)
10. Ethene is used to make a variety of products. Some of these are shown below.
(a) Write the molecular formula for ethylene glycol.
1 mark (KU)
(b) Name substance X.
1 mark (PS)
(c) Which test would you use to distinguish between ethane and ethene?
1 mark PS)
11. (a) Draw the full structural formula for butane.
1 mark (KU)
(b) Name the products when butane reacts completely with oxygen.
1 mark (KU)
12. Propene reacts with hydrogen.
(a) Name the type of reaction taking place.
1 mark (KU)
(b) One of the other products is a compound called butadiene.
It decolourises bromine solution quickly.
What does this tell you about butadiene?
1 mark (PS)
13. Decane is a compound found in the kerosene fraction.
(a) To which family of hydrocarbons does decane belong?
1 mark (KU)
(b) Decane can be broken down into a mixture of saturated and unsaturated hydrocarbons.
(i) What is meant by a saturated hydrocarbon?
1 mark (KU)
(ii) Decane can break down in the following way:
Write down the molecular formula for X.
1 mark (PS)
14. The higher the octane number of a fuel, the more efficiently it burns. The bar chart below shows the octane numbers for some hydrocarbons.
(a) Describe the trend shown by the chart for the alkanes.
1 mark (PS)
(b) From the chart, predict the octane number of the alkane with 3 carbon atoms.
1 mark (PS)
(c) What general statement can be made about the octane number of the alkenes compared with the alkanes?
1 mark (PS)
15. Heptane can be cracked using aluminium oxide as the catalyst.
One of the reactions which takes place is
C7H16 (l) C3H6 (g) + X
heptane
(a) Draw the full structural formula for heptane.
1 mark (KU)
(b) Write the molecular formula for X.
1 mark (PS)
(c) Name the product C3H6.
1 mark (PS)
(d) Aluminium oxide is a white solid but at the end of the experiment it is covered in a black substance.
Suggest what the black substance could be.
1 mark (PS)
16. Petrol and diesel are mixtures of hvdrocarbons which are used as fuels for cars.
(a) What is a hydrocarbon?
1 mark (KU)
(b) Diesel has a higher boiling point than petrol. Which is more flammable, diesel or petrol?
1 mark (KU)
(c) Octane is a hydrocarbon found in petrol.
It can be obtained by cracking larger hydrocarbon molecules.
Write the molecular formula for X.
1 mark (PS)
17. Butene has the structural formula shown below.
(a) Butene reacts with hydrogen gas.
(i) Name the type of chemical reaction which takes place when
butene reacts with hydrogen gas, H2.
1 mark (KU)
(ii) Write the molecular formula for the product of the reaction.
1 mark (PS)
18. Gasoline and gas oil are two of the fractions which can be obtained from crude
oil. Gas oil can be cracked to give more gasoline.
(a) State two ways in which the molecules produced by cracking can be different from the molecules in the gas oil.
2 marks (KU)
(b) Chart A shows the fractions supplied by distilling crude oil. Chart B shows the demand for these fractions.
Explain why gas oil is cracked to produce gasoline.
2 marks (PS)
Topic 6 Homework– Hydrocarbons
Credit Level
1. Many compounds contain carbon, hydrogen and oxygen.
A
BC
D
E
(a) Identify the two compounds which have the same molecular formula.
1 mark (PS)
(b) Identify the compound which has the general formula CnH2nO.
1 mark (PS)
2. Hydrocarbons contain hydrogen and carbon only.
(a) Identify the two hydrocarbons which would quickly decolourise
bromine solution.
1 mark (PS)
(b) Identify the isomer of the hydrocarbon in box D which belongs to a different homologous series.
1 mark (PS)
3. The names of some hydrocarbons are shown in the grid.
Acyclobutane / B
cyclopentane / C
butane
D
propane / E
ethane / F
butene
(a) Identify the hydrocarbon which is a liquid at 25 °C.
You may wish to use the data booklet to help you.
1 mark (PS)
(b) Identify the two isomers.
1 mark (PS)
(c) Identify the hydrocarbon that reacts quickly with bromine solution.
1 mark (PS)
4. The grid shows the formulae of six oxides.
H2O / NO2 / K2O
D / E / F
CaO / CO / SO2
(a) Identify the oxide produced by the sparking of air in car engines.
1 mark (KU)
(b) Identify the two oxides produced by burning hydrocarbons.
1 mark (KU)
5. Propene has the structural formula shown below.
Propene quickly decolourises bromine water, Br2(aq).
(a) (i) Name the type of chemical reaction which takes place when propene reacts with bromine water.
1 mark (KU)
(ii) Draw the full structural formula for the product of the reaction.
1 mark (PS)
6. Methane (CH2), ethane (C2H6) and propane (C3H10) are the first three members of the alkanes.
(a) State the general formula for the alkanes.
1 mark (KU)
(b) The ninth member of the alkanes is nonane (C9H20).
(i) Predict the boiling point of nonane.
You may wish to use page 6 of the data booklet to help you.
1 mark (PS)
(ii) Nonane can be cracked to produce smaller, more useful hydrocarbons. A catalyst is used to speed up this reaction. Suggest another reason for using a catalyst.
1 mark (KU)
(c) Alkanes can be made by the reaction of sodium with iodoalkanes.
For example, butane can be made from iodoethane.
Butane can also be made using two different iodoalkanes.
Name the two iodoalkanes.
1 mark (PS)
7. In industry, ethanol (alcohol) can be produced from ethene as shown below.
(a) Name the type of chemical reaction taking place.
1 mark (PS)
(b) Draw a structural formula for the product of the following reaction:
1 mark (PS)
8. Camping gas contains propane and butane.
Propane and butane are members of the alkane homologous series.
What is meant by the term "homologous series"?
1 mark (KU)
9. Haloalkanes are alkane molecules with a hydrogen atom replaced by a halogen
atom.
The name of the haloalkane depends on the position of the halogen atom in the molecule.
1-chlorobutane 2-chlorobutane
Describe two trends shown by the information in the bar chart.
2 marks (PS)
10. Fractions which are surplus to requirements can be cracked.
(a) Give a reason for cracking fractions.
1 mark (KU)
(b) A catalyst is used to speed up this process. Suggest another reason for using a catalyst.
1 mark (KU)
11. Dienes are a homologous series of hydrocarbons which contain two double bonds per molecule.
(a) What is meant by the term "homologous series"?
1 mark (KU)
(b) Suggest a general formula for the dienes.
1 mark (PS)
(c) Write the molecular formula for the product of the complete reaction of pental,3-diene with bromine.
1 mark (PS)
(d) Draw a full structural formula for, an isomer of buta-l,3-diene which contains only one double bond per molecule.
1 mark (PS)
12. The OXO Process involves the reaction between an alkene and synthesis gas (a mixture of carbon monoxide and hydrogen).
The product is an alcohol with one carbon atom more than the alkene.
For example,
(a) Draw the formula for an alkene which would give the following alcohol.
1 mark (PS)
(b) Draw the formula for the alcohol which would be formed from ethene.
1 mark (PS)
13. The full structural formulae below represent two members of a homologous
series of compounds called the cvcloalkenes.
(a) What is the general formula for the cycloalkene series?
1 mark (PS)
(b) Draw the full structural formula for the cycloalkene with five carbon atoms.
1 mark (PS)
(c) cyclobutene reacts with bromine solution.
Write the molecular formula for the compound formed.
1 mark (PS)
Topic 6 Homework - Hydrocarbons