General Instructions

Reading time – 5 minutes

Working time – 2 hours

Board approved calculators may be used
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Write using black or blue pen
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Draw diagrams using pencil
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A data sheet and a Periodic Table are provided
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Write your student number and/or name at the top of every page
Total marks – 75
Attempt ALL questions
Section I – Pages 2–8
20 marks
Attempt Question 1–20
Allow about 35 minutes for this section
Section II –
55 marks
Pages 9–21
Attempt Questions 21–35
Allow about 1 hour 25 minutes for this section
This paper MUST NOT be removed from the examination room
STUDENT NUMBER/NAME: ……………………..

STUDENT NUMBER/NAME: ……………………..
20 marks
Attempt Questions 1–20
Allow about 35 minutes for this section
Select the alternative A, B, C or D that best answers the question and indicate your choice with a cross (X) in the appropriate space on the grid below.
A B C D
1
A
11
B C D
2
3
4
12
13
14
5
6
7
8
9
10
15
16
17
18
19
20
2

STUDENT NUMBER/NAME: ……………………..
1 An isotope of element X is represented by the symbol shown below.
84 X
36
Which statement is correct about element X and its atomic number?
(A) X is polonium, atomic number 36.
(B) X is polonium, atomic number 46.
(C) X is krypton, atomic number 36.
(D) X is krypton, atomic number 84.
2 Which of the following contains only pure substances?
(A) Copper, hydrogen, sugar and gold
(B) Diamond, oil, steel and wood
(C) Petrol, aluminium, fertiliser, oxygen
(D) Rain water, sugar, sea salt and air
3 What is the correct electronic configuration for sulfur?
(A) 6,3
(B) 2,14
(C) 2,8,6
(D) 2,8,8,6
4 The table below lists the melting points and electrical conductivities of four elements.
Element I II III IV
Melting Point (°C)
Conductivity (MS m
−1
)
98
21
113
10
−21
650
23
3550
10
−17
Which element has a covalent network structure?
(A) Element I
(B) Element II
(C) Element III
(D) Element IV
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STUDENT NUMBER/NAME: ……………………..
5 A student carries out an investigation, in which calcium carbonate is decomposed by heat, releasing a gaseous product.
Which is best used as an identifying test for this gaseous product?
(A) Insert a glowing splint into the gas.
(B) Bubble the gas through limewater (saturated calcium hydroxide solution).
(C) Expose the gas to a flame or spark.
(D) Measure the solubility of the gas in water.
6 Which of the options below describes the relationship between commercial price, chemical activity and abundance of common metals?
Activity Abundance Commercial price
(A) Low High High
(B) High Low Low
(C) Low High Low
(D) Low Low Low
7 A pure gold ancient Byzantine coin has a mass of 4.40 grams.
How many atoms of gold does this coin contain?
(A)
1.235 × 10 22
(B) 1.345 × 10
22
(C) 1.369 × 10
22
(D) 3.703 × 10 26
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STUDENT NUMBER/NAME: ……………………..
8 Which of the following shows the correct half equations and net ionic equation, for the reaction of aluminium metal with dilute sulfuric acid?
Half equation Half equation Net ionic equation
(A) Al(s) → Al 3+ ( aq ) + 3e − 2H + ( aq ) + 2e − → H
2
( g ) 2Al( s ) + H
2
SO
4
( aq ) → Al
2
SO
4
( aq ) + H
2
( g )
(B)
Al 3+ ( aq ) + 3e
− → Al( s ) H
2
( g )
− → 2H + ( aq ) + 2e
−
2Al 3+ ( aq ) + 3H
2
( g ) → 2Al( s ) + 6H + ( aq )
(C)
Al 3+ ( aq ) + 3e
− → Al( s ) H
2
( g ) → 2H + ( aq ) + 2e
−
Al
2
SO
4
( aq ) + H
2
( g ) → 2Al(s) + H
2
SO
4
( aq )
(D) Al( s ) − → Al 3+ ( aq ) + 3e − 2H + ( aq ) + 2e − → H
2
( g ) 2Al( s ) + 6H + ( aq ) → 2Al 3+ ( aq ) + 3H
2
( g )
9 Which statement is correct about elements, represented by P, Q, R, S and T, on the periodic table below?
P Q R
S
T
(A) P has a higher electronegativity and higher combining power than T.
(B) S has a lower electronegativity than R and the same combining power as P.
(C) R has a lower electronegativity than Q and the same combining power as T.
(D) Q has a higher electronegativity than T and the same combining power as R.
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STUDENT NUMBER/NAME: ……………………..
Refer to the following information to answer Questions 10 and 11.
Titanium is used for artificial hip replacements and aircraft engine construction. Its extraction includes the reaction of titanium (IV) chloride with magnesium, at 800ºC, to produce titanium metal and magnesium chloride.
10 Which is the best explanation for this reaction taking place, under these conditions?
(A) Titanium metal is less reactive than magnesium.
(B) Titanium chloride is more stable than magnesium chloride.
(C) Magnesium chloride is insoluble in water.
(D) The reaction is endothermic.
11 What mass of magnesium metal is needed to produce 500.0 g of titanium?
(A) 161 g
(B) 254 g
(C) 322 g
12 Gaseous titanium(IV) chloride is produced in a furnace at 900ºC by the reaction:
(D) 508 g
2FeTiO
3
( s ) + 7Cl
2
( g ) + 6C( s ) → 2TiCl
4
( g ) + 2FeCl
3
( l ) + 6CO( g )
What is the volume of chlorine gas required to produce 100 L of titanium chloride in this reaction?
(A) 100 L
(B) 200 L
(C) 350 L
(D) 1400 L
6

STUDENT NUMBER/NAME: ……………………..
13 Which solution contains the greatest number of solute particles?
(A) 20 mL of 0.10 mol L
−1
LiF
(B) 10 mL of 0.20 mol L
−1
MgI
2
(C) 10 mL of 0.20 mol L
−1
NH
3
(D) 10 mL of 0.10 mol L
−1
sucrose (C
12
H
22
O
11
)
14 What mass of anhydrous sodium carbonate (Na
2
CO
3
) is required to produce 250.0 mL of a 0.0500 mol L
−1
solution?
(A) 0.0125 g
(B) 1.32 g
(C) 12.5 g
(D) 13.25 g
15 Which intermolecular forces are dominant in gaseous hydrogen sulfide H
2
S (g) ?
(A) Dispersion forces and dipole-dipole attraction
(B) Dispersion forces and hydrogen bonding
(C) Dipole-dipole attraction and hydrogen bonding
(D) Dispersion forces only
16 Which statement explains the importance of water’s heat capacity, to aquatic organisms on Earth?
(A)
Water’s high heat capacity results in rapid temperature changes.
(B) Water’s low heat capacity results in rapid temperature changes.
(C)
Water’s high heat capacity prevents rapid temperature changes.
(D) Water’s low heat capacity prevents rapid temperature changes.
17 Which of the following identifies the original source of energy in fossil fuels?
(A) Solar energy captured millions of years ago through photosynthesis
(B) Microscopic organisms trapped in sediments on the ocean floor
(C) Carbon dioxide in the atmosphere
(D) Radioactive elements within the earth
7

STUDENT NUMBER/NAME: ……………………..
18 Two allotropes of carbon (I and II) are represented below.
Carbon atom
Which statement is correct of these allotropes?
(A) Allotrope I is an element and allotrope II is a compound.
(B) Allotrope I has the same boiling point as allotrope II.
(C) Allotrope I is non-conductive whereas allotrope II is conductive.
(D) Allotrope I is soft whereas allotrope II is extremely hard.
19 Which of the following statements is correct of the hydrocarbons, hexane and 2-hexene?
(A) Both have the same molecular formula.
(B) Both are in the same homologous series.
(C) Both are gases under room conditions.
(D) 2-hexene is more reactive than hexane.
20 Which statement describes the function of a catalyst?
(A) Raise the activation energy and increase the rate of a chemical reaction.
(B) Lower the activation energy and increase the rate of a chemical reaction.
(C) Raise the activation energy and increase the yield of a chemical reaction.
(D) Lower the activation energy and ensure the reaction goes to completion.
8

STUDENT NUMBER/NAME: ……………………..
55 marks
Attempt All Questions
Allow about 1 hour and 25 minutes for this section
Answer the questions in the spaces provided.
Show all relevant working in questions involving calculations.
Question 21 (4 marks)
(a) Sketch a diagram to model the type of bonding found in metals.
Marks
2
(b) Referring to your sketch, describe this type of bonding and relate it to an important property of metals.
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STUDENT NUMBER/NAME: ……………………..
Question 22 (4 marks)
(a) Write a balanced equation, including states, for the reaction of calcium metal with chlorine, producing calcium chloride.
Marks
1
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(b) In the space below, use Lewis electron dot notation to show the electronic changes that occur in this reaction.
Question 23 (3 marks)
The melting point of carbon dioxide is –57°C, while that of silicon dioxide is 1600°C.
(a) Write the formula for silicon dioxide and state the valency shown by silicon.
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(b) Account for the high melting point of silicon dioxide.
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1
2
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10

STUDENT NUMBER/NAME: ……………………..
Question 24 (3 marks)
Sodium sulfate is soluble in water, while barium sulfate is not.
A student performed a first-hand investigation to analyse a mixture of sodium sulfate and barium sulfate. The student carried out the following steps:
1.
A sample of the mixture was weighed accurately.
2.
The sample was mixed with water in a 250 mL beaker.
3.
A filter paper was weighed accurately.
4.
The mixture was filtered through the filter paper.
5.
The filter paper and solid residue were removed and dried in an oven.
6.
When cool, the filter paper and residue were re-weighed.
Marks
(a) Explain why filtering is the most effective technique for separating this mixture.
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(b) The following data was obtained by the student:
Mass of sample mixture provided = 15.55 g
Mass of dry filter paper = 0.95 g
Mass of dry filter paper and residue = 6.35 g
Determine the percentage of barium sulfate, by mass, in the original sample.
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11

STUDENT NUMBER/NAME: ……………………..
Question 25 (3 marks)
A porcelain crucible was weighed empty, then with pieces of magnesium ribbon inside it.
The crucible was heated, using the equipment shown below, with the crucible lid being raised periodically to admit air.
Once the reaction was complete, the crucible was cooled and weighed. magnesium
Bunsen burner crucible pipe clay triangle tripod heat resistant mat
The measurements are shown in the table below:
Equipment
Crucible
Crucible + magnesium
Crucible after cooling
Mass (g)
10.524
11.277
11.766
Identify the product and determine its empirical formula from these measurements.
Show all working.
Marks
3
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STUDENT NUMBER/NAME: ……………………..
Question 26 (6 marks)
The atomic radii of some elements are shown below.
Element
Lithium
Boron
Carbon
Atomic Radius (pm)
152
88
77
Nitrogen
Oxygen
Fluorine
Neon
70
66
68
70
(a) Plot a line graph of atomic radius, against atomic number for these elements.
Marks
3
(b) From your graph, predict the atomic radius of beryllium.
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(c) Explain the trend shown in the graph.
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2
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STUDENT NUMBER/NAME: ……………………..
Question 27 (3 marks)
Metals have been used, uncombined and as alloys, for many purposes for thousands of years .
Marks
(a) Name ONE alloy used in ancient times and identify its constituents.
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(b) Identify why there are more metals available for use today than there were 200 years ago. Include ONE example of such a metal in your answer.
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STUDENT NUMBER/NAME: ……………………..
Question 28 (3 marks)
During the course of study, you performed a first-hand investigation and researched secondary sources to determine the metal activity series.
(a) Outline how you performed ONE first-hand investigation.
Marks
2
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(b) Identify ONE property that you learnt about from secondary sources and describe how this property relates to metal activity.
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Question 29 (5 marks)
(a) Describe the structure and shape of the ammonia molecule.
1
2
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(b) With the aid of an electron dot diagram, describe hydrogen bonding between ammonia molecules.
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STUDENT NUMBER/NAME: ……………………..
Question 30 (4 marks)
(a) Compare the nature of the ions in solid potassium nitrate, to ions in aqueous potassium nitrate.
Marks
2
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(b) Potassium nitrate dissolves endothermically, with heat of solution +36 kJ mol
−1
.
Calculate the final temperature, if 10.0 g of potassium nitrate is dissolved in 100 mL of water at 20°C.
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2
16

STUDENT NUMBER/NAME: ……………………..
Question 31 (4 marks)
The graph below shows the mass of lead (II) iodide precipitate, produced when increasing volumes of sodium iodide solution are mixed with 20.0 mL of lead (II) nitrate solution.
A volume of NaI
(aq)
added (mL)
(a) Write an ionic equation to represent the production of the precipitate.
Marks
1
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(b) Explain the shape of the graph, including the significance of point A.
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3
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STUDENT NUMBER/NAME: ……………………..
Question 32 (4 marks)
In a student's report on separating substances by distillation, the following diagram was included.
Marks
(a) The apparatus represented by this drawing is both unsafe and ineffective.
Describe TWO faults in this set-up and how each should be fixed.
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(b) Identify the property on which this separating technique is based.
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(c) Name an industrial mixture that is separated by distillation.
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1
1
18

STUDENT NUMBER/NAME: ……………………..
Question 33 (3 marks)
Volatility can be measured by recording the pressure, caused by the compound’s vapour, in a closed container. The table below shows the effect of increasing temperature on the vapour pressure of octane.
Temperature (°C)
0
Vapour pressure (kPa) 0.4
20
1.3
40
4.1
60
10.4
80
23.3
(a) Define the volatility of a substance.
Marks
1
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(b) Explain the relationship between vapour pressure and temperature, as shown in the table.
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2
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19

STUDENT NUMBER/NAME: ……………………..
Question 34 (3 marks)
A student discovered that Bunsen burners in her school burnt natural gas (mostly methane gas).
She also discovered that different flames indicated different combustion products and heats of combustion, as shown in the table below.
Flame colour
Main combustion products
Heat of combustion
(kJ mol
−1
)
Blue
Light purple
/mauve
Yellow
Carbon dioxide and water
Carbon monoxide and water
Carbon and water
804
521
410
(a) Identify the most efficient flame for heating water and justify your answer.
Marks
2
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(b) Write a balanced chemical equation for burning methane, when a light purple/mauve flame is produced.
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20

STUDENT NUMBER/NAME: ……………………..
Question 35 (3 marks)
During the course of study, you performed a first–hand investigation on the effect of changing concentration on the rate of a chemical reaction.
(a) Outline the method used in this investigation.
Marks
2
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(b) State the conclusion made after the investigation.
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End of paper
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