Higher Section 5
Fuels Homework
Fuels Homework 1
1. Naphtha fractions from a distillation column contain a mixture of many
hydrocarbons with low octane ratings. To improve its qualities as a petrol (i.e.
increase its octane rating) the naphtha is passed over a catalyst of aluminium oxide
coated with platinum.
The three reactions shown below are typical of this process.
H
H
H
H
H
H
H
C
C
C
C
C
C
H
H
H
H
H
H
H
a) What is the name given to this type of process?
1
b) Name the three compounds formed.
3
c) Why are the products better fuel molecules for a car engine?
1
2. Explain why the following compounds may be added to petrol.
a) Tetraethyllead (C2H5) 4Pb.
1
b) butane and pentane.
1
3. a) Describe the advantages of using the following as alternatives to petrol.
i) ethanol.
1
ii) hydrogen.
1
iii) methanol.
1
b) For methanol, describe two disadvantages in its use as a motor vehicle fuel.
1
4. Hydrogen and ethanol are both being put forward as alternatives to petrol. Describe the
process used to produce
a) ethanol.
1
b) hydrogen.
1
5. a) Draw the extended structural formulae for all 5 isomers of hexane.
5
b) Name all 5 isomers using systematic nomenclature.
5
6. Draw the extended structural formula for
a) 2,4-dimethylheptane.
b) 3-ethyl-2-methylpentane.
c) 3-methylbut-1-yne.
3
Total = 26 marks
Fuels Homework 2
1. Write the systematic names for
H
a)
H
H
H
C
C
H
H
H
C
C
H
H
b)
H
H
H
C
C
C
C
H
H
H
H
C
H
H
H
CH2
CH3
C
CH2
CH
CH2
CH3
CH3
H
CH3
CH2
CH3
2
2. Write the structural formulae and names of 3 isomers of pentene.
3
3. Identify the homologous series each of the following molecules belongs to and name the
functional group present.
H
a)
H
H
O
b)
H
C
C
C
H
H
H
CH3
C
H
O
CH2
CH3
c)
d)
H
e)
H
H
C
C
H
H
H
H
O
H
H
N
C
O
H
H
C
C
H
H
H
H
f)
C
CH3CHCHCH3
O
6
4. Using the simplified symbol for a benzene ring draw the structural formulae for
a) Methylbenzene (toluene).
b) Benzoic acid
2
5. Draw the full structural formulae for each of the following compounds.
a) Butan-2-ol
b) Pentanal
c) Ethanoic acid
3
6. Give the systematic names for the following compounds.
O
OH
a)
CH3
b)
CH
C
CH3
CH2
CH
c)
CH3
CH3
CH2
CH
CH3
3
CH3
7. Give the molecular formula for the compound shown below.
CH3
CH3
1
Total = 20
Fuels Homework 3
1. For each of the following hydrocarbons:
i. draw its full structural formula
ii. write its shortened structural formula
a) 2-methylpentane
2
b) 2,5-dimethylheptane
2
c) 3-ethylhex-1-ene
2
2. Give the systematic name for each of the following hydrocarbons
a)
b)
c)
3. Why can substances b and c in question 2 be regarded as isomers?
3
1
4. The following molecule reacts rapidly with bromine:
a) Draw the full structural formula of the molecule produced.
1
b) Give the systematic name for the product molecule.
1
c) Name the type of reaction by which the bromination takes place.
1
5. Using shortened structural formulae, write an equation for the reaction of
hex-3-ene with hydrogen bromide.
2
Total = 15
Fuels Homework 4
1. A propyne molecule contains a triple bond:
a) Draw the full structural formula for propyne.
1
b) Draw a dotted line around the functional group in the structural formula.1
c) How many electrons are shared in a triple bond?
1
d) Explain why propyne is an unsaturated hydrocarbon?
1
e) Draw the full structural formula of the molecule produced when one propyne
molecule reacts with one bromine molecule.
1
f) Give the systematic name for this product.
1
2. Draw the full structural formula for;
a) 3-methylpent1-yne
b) 4-ethylhex-2-yne
2
3. Give the systematic name for each of the following hydrocarbons;
a) CH3CH2C≡CCH2CH2CH2CH3
1
b) CH3CH2CH(CH2CH3)C≡CCH3
1
4. Draw the full structural formula for:
a) chloroethene b) trichloromethane
b) tetrafluoroethene
d) 1,2-dichloro-1,1,2,2-tetrafluoroethane
4
5. Of the compounds listed in questions 4, which one is:
a) used as a feedstock for manufacturing PVC?
1
b) an example of a CFC
1
6. The use of CFC gases as refrigerants and propellants is now banned internationally.
a) what problem do CFC gases cause in the atmosphere?
1
b) why does rain not wash CFC gases out of the atmosphere?
1
c) what causes CFC molecules to split up in the uppermost atmosphere?
1
d) what atom from the CFC molecule causes the damage in the upper most
atmosphere?
1
Total = 20