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2003HIGHER SCHOOL CERTIFICATE
Trial Examination Paper
Chemistry
Section I
Section II
General Instructions
Reading time - 5 minutes Working time - 3 hours Write using black or blue pen Draw diagrams using pencil Board-approved calculators may
be used A data sheet and a Periodic Table
are provided at the back of this paper
Write your Student Number at the top of pages 8, 13, 17 and 21
Total Marks - 100
Pages 2-24
75 marksThis section has two parts, Part A and Part B
Part A - 15 marks Attempt Questions 1-15 Allow about 30 minutes for this part
Part B - 60 marks Attempt Questions 16-27 Allow about 1 hour and 45 minutes for this part
Pages 25-31
25 marks Attempt ONE question from Questions 28-32 Allow about 45 minutes for this section
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Section I75 marks
Part A - 15 marksAttempt Questions 1-15Allow about 30 minutes for this part
Use the multiple-choice answer sheet.
Select the alternative A, B, C or D that best answers the question. Fill in the response oval completely.
Sample: 2 + 4 = (A) 2 (B) 6 (C) 8 (D) 9 A B C D
If you think you have made a mistake, put a cross through the incorrect answer and fill in the new answer.
A B C D
If you change your mind and have crossed out what you consider to be the correct answer, then indicate the correct answer by writing the word correct and drawing an arrow as follows.
correct
A B C D
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1 What is the systematic name for this monomer?
(A) Polystyrene.
(B) Vinyl chloride.
(C) Ethenyl benzene.
(D) Styrene.
2 Which diagram below best represents the polymerisation of ethene?
(A) CHCN=CH2 forming -CHCN-CH2-CHCN-CH2-
(B) CH2=CH2 forming -CH2-CH2-CH2-CH2-
(C) C6H12O6 forming -C6H10O5-C6H10O5-
(D) CHCl=CH2 forming -CHCl-CH2-CHCl-CH2-
3 Scientists think that cellulose may be able to be turned into a raw material for fuel to reduce
our dependence on fossil fuels. What is important about the chemical structure of cellulose
that may allow it to be used for this purpose?
(A) It contains at least two -OH groups and can be made into a condensation polymer.
(B) It contains C, H, and O.
(C) It is composed of simple sugar molecules that can provide energy.
(D) It is an addition polymer.
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4 Under which conditions is the fermentation of sugars promoted?
(A) Warm, moist and with plenty of carbon dioxide.
(B) Warm, moist and with plenty of oxygen.
(C) Hot, dry and with plenty of sugar.
(D) Hot, moist and plenty of sugar.
5 Four beakers, each containing a metal chloride solution, were set up in a laboratory.
Beaker A contained CuCl2, Beaker B contained PbCl2, Beaker C contained FeCl2 and
Beaker D contained NaCl.
What would happen in each beaker when a piece of steel wool was placed into the beaker?
(A) No reaction in any beaker
(B) The steel wool would displace the metal ions in Beaker A.
(C) The steel wool would displace the metal ions in Beaker D.
(D) The steel wool would displace the metal ions in Beakers A and C.
6 Oxides of sulfur and nitrogen contribute to acid rain.
Which is the major source of sulfur dioxide (SO2) in the atmosphere?
(A) Internal combustion engines.
(B) Volcanic eruptions.
(C) Bacterial action at great depths in the ocean.
(D) Slow reaction between sulfur and oxygen in the upper atmosphere.
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7 Solutions of which of the following compounds would all basic?
(A) NaOH, NH4Cl and CaO.
(B) SO2, NH4Cl and NO2.
(C) NaOH, MgO and CaO.
(D) NaOH, NH4Cl and CO2.
8 Phenophthalein is a commonly used indicator. It is colourless in solutions of pH 8 or less
and pink in more basic solutions. What colour(s) would a solution of lemon juice and a
solution of ammonia appear if phenophthalein were added to each?
(A) Colourless, pink
(B) Coulourless, colourless
(C) Pink, pink
(D) Pink, colourless
9 Which of these statements best describes the differences between weak and dilute acid
solutions?
(A) A weak acid is not fully ionised and a dilute acid contains only a small amount of
solute.
(B) A weak acid contains only a small amount of solute and a dilute acid is not fully
ionised.
(C) A weak acid is fully ionised and a dilute acid is not fully ionised.
(D) A weak acid is fully ionised and a dilute acid contains a small amount of
solute.
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10 Which words best complete this sentence?
Neutralisation is a __________ transfer reaction that is ____________.
(A) electron, endothermic
(B) proton, endothermic
(C) electron, exothermic
(D) proton, exothermic
11 What is the systematic name for this compound?
(A) 4,6-dichloro-5,5-difluorohexane
(B) 1,3-dichloro-2,2-difluorohexane
(C) 4,6-difluoro-5,5-dichlorohexane
(D) 1,3-difluoro-2,2-dichlorohexane
12 CFC’s cause the breakdown of ozone in the stratosphere. Which bond in the CFC causes
this problem?
(A) C-H
(B) C-Cl
(C) C-C
(D) C-F
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13 Which molecule contains a coordinate covalent bond?
(A) Ozone
(B) Oxygen
(C) ammonia
(D) water
14 Chemists monitor the concentrations of dissolved ions in the water supply.
Which is the most important factor that affects the concentration of lead ions in water
supplies?
(A) Leaching from rubbish dumps
(B) pH of rain
(C) Rising water table
(D) Agricultural run-off
15 The Haber process for the production of ammonia is an equilibrium process.
N2 (g) + 3H2 (g) 2NH3 (g) H = -92kJ/mol
Which set of conditions would achieve the maximum yield of ammonia?
(A) High temperature and low pressure
(B) High temperature and high pressure
(C) Low temperature and high pressure
(D) Low temperature and low pressure
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Section I (continued) Student Number:____________75 marks
Part B - 60 marksAttempt Questions 16-27Allow about 1 hour and 45 minutes for this part
Answer the questions in the spaces provided.
Show all relevant working in questions involving calculations.
MarksQuestion 16 (8 marks)
(a) Ethanol can be burnt as a fuel. Using ethanol as a fuel would reduce the use of 3
non-renewable fossil fuels.
Outline the processes involved in the industrial production of ethanol from sugar
cane.
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Marks(b) Ethanol is able to be used in cars as an alternative to petrol and diesel.
Evaluate the success of the current usage of ethanol as a car fuel. 5
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Question 17 (6 marks)
(a) The elements with atomic numbers greater than 92 are called transuranic elements.
Describe how these elements are produced. 3
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Marks(b) Carbon-14 is used in radioactive dating. It has a half-life of 5700 years.
Carbon-12 is the most common isotope of carbon and it is not radioactive.
Describe conditions under which a nucleus is unstable. 3
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Question 18 (7 marks).
For the cell: Fe2+ /Fe3+/Pt// Zn2+/Zn.
(a) Draw a labelled diagram of the galvanic cell. 3
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Marks (b) Write the anode half equation. 1
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(c) Determine the cell EMF. 3
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Question 19 (6 marks)
One source of sulfur dioxide in the atmosphere is the smelting of zinc sulfide ore in the
presence of oxygen to form zinc oxide and sulfur dioxide.
(a) Identify two other sources of atmospheric sulfur dioxide. 2
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(b) If all the sulfur in the ore is converted to sulfur dioxide, what volume of SO2 would be
produced at 100kPa and 298K from the smelting of 150kg of zinc sulfide ore? 4
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Question 20 (8 marks)
A manufacturers claim on a bottle of lemonade says that it contains 2.13g of
citric acid per 250mL bottle.
(a) Draw an expanded structural formula of the citric acid molecule. 1
In order to test the manufacturer’s claims, a titration was performed. A 25mL
aliquot of the lemonade was taken and the citric acid was neutralised with 0.005M
sodium hydroxide solution.
(b) Suggest an indicator that would be suitable for this titration. Give ONE
reason why you selected this indicator. 2
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Marks (c) If the manufacturer’s claims were true, then what volume of sodium hydroxide
solution was required for neutralisation of the citric acid? 3
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The sodium hydroxide solution that was used was not a primary standard.
The sodium hydroxide solution had been characterised by titration with a
primary standard.
(d) Why is sodium hydroxide not useful as a primary standard? 2
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Question 21 (8 marks)
Esters are produced by the reaction of an alkanol and an alkanoic acid.
(a) Write a balanced chemical equation to show the production of the ester
pentyl ethanoate. 2
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MarksAlkanols and alkanoic acids both have boiling points higher than those of
the corresponding alkane.
(b) Explain the difference in boiling points between pentane, pentanol and
pentanoic acid. 4
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(c) Identify TWO possible uses for esters such as pentyl acetate. 4
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Question 22 (8 marks)
(a) Atomic absorption spectroscopy is useful in detecting small concentrations
of some ions. Identify the type of ions that AAS can identify. 1
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Marks
The first step in calculating the concentration of an ion present in trace amounts
is the develop a calibration graph such as the one above for lead ions.
(b) Calculate the concentration of lead ions if a sample has an absorbance of 0.35. 1
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(c) Evaluate the effectiveness of AAS measurements in pollution control. 6
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Question 23 (9 marks)
Clean drinking water is important to most people in NSW. Microscopic
membrane filters are an important part of the process of cleaning water supplies.
(a) Describe the design and composition of microscopic membrane filters. 3
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(a) Assess the effectiveness of methods used to purify and sanitise mass water supplies. 6
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Section II Student Number:____________25 marks
Attempt ONE question from Questions 24-28Allow about 45 minutes for this part
Answer the questions in a writing booklet. Extra writing booklets are available.
Show all relevant working in questions involving calculations.
Pages
Question 24 Industrial Chemistry.........................................19
Question 25 Shipwrecks and Salvage....................................20
Question 27 The Chemistry of Art........................................21
Question 28 Forensic Chemistry...........................................22
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Question 24 - Industrial Chemistry (25 marks)
(a) One measure of a nation’s industrial capacity is the amount of sulfuric acid used annually in the country. This arises as a result of the wide variety of uses of sulfuric acid in industry.
(i) Describe one major industrial use of sulfuric acid.
(ii) The main precursor for the production of sulfuric acid issulfur dioxide.
I Write a balanced chemical equation for the conversion of sulfur dioxide to sulfur trioxide.
II Write down the expression for the equilibrium constant for the reaction. (1)
III In a laboratory experiment to model the conversion of sulfur dioxide to sulfur trioxide 12.8 g of sulfur dioxide is injected into a 2.0 litre gas chamber with an excess of oxygen gas over a heat vandium pentoxide catalyst. The system is allowed to come to equilibrium at 320o C. At equilibrium there is 8.0 g of oxygen and 4.4 g of sulfur trioxide present.
Calculate the amount of sulfur dioxide remaining in the vessel and hence determine the value of the equilibrium constant at 400o C. (3)
IV Compare and contrast the conditions which maximise the yield of sulfur trioxide and the actual conditions used in the industrial preparation of sulfur dioxide. (3)
(b) (i) Write balanced half equations for the reactions occurring at the electrodes in the preparation of sodium hydroxide from brine.
(ii) State the advantages and disadvantages of the mercury cell in the production of sodium hydroxide in comparison with the membrane cell method.
(c) (i) Describe an experiment you carried out in the laboratory to produce soap from a fat or oil.
(ii) Compare the conditions you used to make soap in the laboratory with those used in the industrial preparation of soap.
(iii) Describe the structure of a soap particle and use it to explain the emulsifying action of soaps.
(iv) Discuss the environmental impacts of the use of soaps and detergents.
(d) Outline the criteria which would be used in determining the location of a plant to make sodium carbonate by the Solvay Process. (3)
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Question 25 - Shipwrecks, Corrosion and Conservation (25 marks)
(a) (i) Identify ONE origin of minerals in the ocean.
(ii) What is the purpose of the liquid electrolyte in electrochemical
cells?
(iii) Describe the work of Volta and Faraday in increasing our
understanding of electron transfer reactions.
(b) (i) Identify ONE passivating metal.
(ii) Account for the differences in corrosion of active and passivating
metals.
(iii) Evaluate the accuracy and reliability of the experiment that you used
to determine the conditions under which rusting occurs.
(c) (i) Identify ONE factor that affects electrolysis reactions.
(ii) Describe the effect of varying this factor on electrolysis reactions.
(iii) Outline the process of cathodic protection in a wet terrestrial
environment.
(d) (i) Outline the effect of temperature and pressure on the solubility of
gases.
(ii) Explain why people thought that shipwrecks at great depths would
not be corroded as much as those in shallow water.
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