CHAPTER 13 WE RELY ON PETROLEUM
Name:
QUESTIONS
13.1 Fuels for all
Consider the requirements of a fuel for heating and lighting on a camping trip.
1. What criteria would be important in deciding the properties of a suitable fuel for this
situation? You should start by referring to the following (where relevant): combustion
properties, environmental considerations, cost, availability and safety.
2. Use your criteria to determine the best fuel from the following list: paper, wood, coal,
candle wax, alcohol, petrol, LPG, wood and sugar. Justify your choice.
3. Discuss which regions of the world will be most able to deal with tensions about
petroleum reserves and consumption in the future. Justify your choice.
4. Of the problems with petroleum discussed above, which do you believe is the most
significant for the world? Justify your selection and include references to the other
problems.
13.3 Hydrocarbons
5. Give the formula for an alkane having 14 carbon atoms.
6. Give the formula for an alkane having 54 hydrogen atoms.
7. Draw the structures of any six of the alkanes in table 13.1.
8. Complete and balance the following equations.
(a) C2H6(g) + O2(g) 
(b) C5H12(g) + O2(g) 
9. Write a balanced chemical equation for the combustion of an alkane that has six
carbon atoms.
10. Use a molecular modelling kit to construct a model of butane. Rearrange your model to
form 2-methylpropane.
11. Form a model of pentane. How many isomers of pentane can you form?
© John Wiley & Sons Australia, Ltd
1
QUEENSLAND CHEMISTRY
12. Draw each of the isomers of pentane that you construct.
13. Explain the terms saturated and unsaturated in relation to hydrocarbons. Give two
examples of each.
14. Use a molecular modelling kit to form a model of propyne. Rearrange your model to
form 2-methylpropane.
15. Write a balanced equation for the combustion of propyne.
16. Give the structural formula for each of the following.
(a)
Propane
(b)
Hexane
(c)
Propene
(d)
Propyne
17. Name the two compounds produced when propene is completely burned.
18. Give the molecular formula of an alkane having 23 carbon atoms.
19. Deduce the molecular formula of an alkene having 34 carbon atoms.
20. Complete and balance the following reactions to show complete combustion.
(a)
C6H12(g) + O2(g) 
(b)
C7H16(g) + O2(g) 
21. Draw two possible isomers of C6H12.
22. As the molecular size of the alkanes increases, there is a change from the gaseous phase to
the solid phase. Explain why this occurs.
23. Alkynes are more reactive that alkenes. In terms of chemical bonding, explain why this is
the case.
24.
Write a structural formula for each of the following.
(a)
Hept-2-ene
(b)
2-methylbut-2-ene
(c)
Pent-2-yne
25. Name each of the following.
26. Draw a structural formula for each of the following.
(a)
4-methyldec-2-ene
© John Wiley & Sons Australia, Ltd
2
QUEENSLAND CHEMISTRY
(b)
2,4-dimethylnonane
27. The semi-structural formula for methylpropane is CH3CH(CH3)2 and that for
2-methylpentane is CH2CH(CH3)CH2CH2CH3. Write a semi-structural formula for
2,3-dimethylhexane.
28. Write a semi-structural formula for each of the compound(s) in questions 24 to 26.
Review questions
1. Why can petroleum be considered ‘buried sunshine’?
2. Explain why, for most applications, the energy stored in petroleum fuels is more useful
than solar energy.
3. (a) Write an equation for photosynthesis (include energy).
(b) How is this equation similar to, and different from, an equation for burning a
hydrocarbon?
4. Describe how prehistoric green plants are thought to have been transformed into today’s
petroleum reserves, and then relate this process to why petroleum fuels are considered to
be non-renewable.
5. Examine the following graph of petroleum supply and demand in Australia, and answer
the questions that follow.
(a)
What problems do you expect to occur as the demand for petroleum continues to
rise in relation to its supply? Consider economic, social, political, technological
and environmental factors in your response.
(b)
Suggest five Australian government policy measures that could be taken to
prevent or overcome these problems. For each suggestion, identify and explain
one potential barrier to its implementation or success.
6. Rank the following hydrocarbons from those with the lowest boiling point to those with
the highest boiling point: hexane, methane, pentane and octane. Explain your ranking.
7. The molar masses of methane (16 g mol–1) and water (18 g mol–1) are similar. At room
temperature, methane is a gas while water is a liquid. Explain this difference in terms of
intermolecular forces.
8. (a) What is meant by the term hydrocarbon?
(b) Give the names and formulas of three different hydrocarbons, each containing three
carbon atoms.
9. (a) Alkanes and alkenes are types of hydrocarbons. In what way do they differ? Give an
example of each.
© John Wiley & Sons Australia, Ltd
3
QUEENSLAND CHEMISTRY
(b) Write equations for the oxidation of the second member of the alkene series and the
third member of the alkane series.
10. Define the term isomer. Illustrate your answer with formulas for the isomers of pentane
and hexene.
11. Distinguish between saturated and unsaturated hydrocarbons.
12. Write formulas for each of the following hydrocarbons.
(a) An alkane with 22 carbon atoms
(b)
An alkene with 17 carbon atoms
(c)
An alkyne with 13 carbon atoms
13. Name the following organic compounds. (Note: The longest continuous chain may not be
shown in a straight line.)
14. Draw structural formulas for each of the following compounds.
(a) 3,3-dimethylpentane
(b) 2,3-dimethylhexane
(c) 3-ethylhexane
(d) 3-ethylheptane
(e) 2,2,4-trimethylpentane
(f) 3-ethyl-2,4-dimethyloctane
15. Write full and semi-structural formulas for each of the following.
(a) 2-methylheptane
(b) Oct-3-ene
(c) 2,3-dimethyl-but-2-ene
(d) Pent-2-yne
(e) Cyclohexane
(f) 2,6-dimethylhept-3-ene
16. Name each of the following.
Notes:
© John Wiley & Sons Australia, Ltd
4
QUEENSLAND CHEMISTRY
© John Wiley & Sons Australia, Ltd
5