ANCQ 2016 YEARS 7 & 8
2016 RACI AUSTRALIAN NATIONAL CHEMISTRY QUIZ YEARS 7 & 8
DATA
The names and symbols of some elements are given below:
Al
Ca
C
Cl
Cu
aluminium
calcium
carbon
chlorine
copper
gold
helium
hydrogen
iron
lead
Au
He
H
Fe
Pb
magnesium
mercury
nitrogen
oxygen
phosphorus
Mg
Hg
N
O
P
silicon
silver
sodium
sulfur
zinc
Si
Ag
Na
S
Zn
The structure of molecules:
Molecules are two or more atoms chemically joined (“bonded”). Structural formulae show the arrangement of atoms in molecules.
Single () and double (═) strokes represent bonds holding atoms together. Hydrogen atoms only have one bond joining them to
other atoms, oxygen atoms have a total of two bonds and carbon atoms have a total of four bonds. Sometimes molecules
containing carbon can be drawn shorthand, as below:
Cyclohexene
Cyclohexene (shorthand)
Units of measure
Symbol
m
c
k
Name
milli
centi
kilo
Value
1/1000
1/100
1000
Metric units
Quantity
1L
1 mL
Equivalent metric unit
3
1 dm
3
1 cm
Image Acknowledgements:
The following images have been reproduced with permission from the following sources:




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Information for Q9/Q10: Nevastane & TOTAL
Q12: Raeky/Wikipedia
Q14a: Виталий Смолыгин/publicdomainpictures.net
Q14b: Ben Mills and Jynto/Wikipedia
Q14c: Linnikh/ Wikipedia
Q14d: Owen Thomas/123rf.com
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ANCQ 2016 YEARS 7 & 8
Information for Questions 1, 2 and 3.
Nitroglycerin, a compound of nitrogen, oxygen, carbon and hydrogen, was first made in 1847 and was found to be highly
explosive. Alfred Nobel manufactured it, but it was found to be too unstable and dangerous. Nobel combined nitroglycerin with
diatomaceous earth to make dynamite. Diatomaceous earth is a type of a soft sedimentary rock that generally contains silica, SiO2,
alumina, Al2O3, and iron(III) oxide, Fe2O3.
Question 1.
The structure of nitroglycerin is shown on the right.
Which of the following statements is TRUE about
nitroglycerin?
A.
B.
C.
D.
It only contains three elements.
It only contains two non-metals.
Each molecule contains 8 nitrogen atoms.
Each molecule contains 3 carbon atoms.
Question 2.
When nitroglycerin explodes, it breaks down (decomposes) into simpler chemicals. It does not react with anything else initially.
Which of the following is NOT a possible product when nitroglycerin initially explodes?
A.
Fe
B.
CO2
C.
N2
D.
O2
7
D.
8
Question 3.
How many different elements are present in dynamite?
A.
4
B.
6
C.
Question 4.
A student wrote down some physical and chemical changes around their home:
1. Boiling an egg
2. A piece of iron rusting
3. Ice melting in a glass
4. Water boiling in a kettle
5. Baking bread
6. Wood burning
A chemical change involves at least one new substance being formed while a physical change may result in a change of state, but
no new substances are formed.
The physical changes were
A.
2 and 6 only.
B.
3 and 4 only.
C.
3, 4 and 5 only.
D.
1, 3, 4 and 5 only.
Question 5.
Flour is made by crushing cereal grains, such as wheat, which releases starch and protein. Some simple breads are made from
flour, yeast, water and salt. When making these simple breads, the following steps occur:

When flour is added to water and kneaded, some of the proteins swell up to make gluten, to make the bread spongy.

Leavening of the bread happens when yeast, a microscopic fungus, helps break down starch to make glucose, and then
causes the glucose to produce carbon dioxide, which allows the bread to rise.

The amount of salt controls the rate at which some enzymes convert starch to carbon dioxide.

Once baking in an oven, the pockets of trapped carbon dioxide expand and cause the dough to expand even further.
Damper is a traditional Australian form of bread and is often made from only flour and water. Sometimes some bicarb soda (sodium
hydrogen carbonate, NaHCO3) is added to the flour and water. The reason for adding bicarb soda is to
A.
C.
help the yeast break down glucose.
help produce some carbon dioxide.
B.
D.
help the yeast break down gluten.
replace the gluten in the bread.
Question 6.
Alloys are mixtures that contain large amounts of metals, and maybe a small amount of non-metals. Some examples are listed
below.
Alloy
Elements in alloy
Pig iron
Iron, carbon
Nickel, manganese, aluminum, silicon
 Alumel
Zinc, aluminum, magnesium, copper
 Zamak
Guanin
Copper, manganese, iron, sulfur
Which alloy above contains ONLY metals?
A.
Pig iron
B.
Alumel
C.
Zamak
D.
Guanin
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ANCQ 2016 YEARS 7 & 8
Question 7.
Colloids are a type of mixture. The particles are evenly dispersed, like the particles in a sugar solution, but they are also like
suspensions (for example, muddy water), because the particles are not soluble. Paints are a colloid called a sol, where the
solid paint particles are mixed in the liquid. Flyspray is a colloid called an aerosol, where either solid or liquid particles are
mixed in a gas. Styrofoam is a colloid called a foam, where gas is mixed through either a liquid or solid.
Which of the following is NOT a colloid?
A.
C.
Fog, where liquid water is mixed in air.
.
Salt water, where table salt is mixed in liquid water.
B.
D.
Shaving cream, where there is gas mixed in a liquid.
Bushfire smoke, where solid ash is mixed in air.
Question 8.
Some ancient and medieval chemists, called alchemists, thought all metals were formed from mercury, also commonly called
quicksilver. They believed that different metals, particularly gold, could be produced by varying the quality and quantity of sulfur
reacted with mercury. Mercury is found in the mineral cinnabar as mercury(II) sulfide, a compound of mercury and sulfur.
The formula for mercury(II) sulfide is
A.
AgS.
B.
AuS.
C.
McS.
D.
HgS.
Information for Questions 9 & 10.
Chocolate comes originally from cocoa beans, which grow inside pods on cacao trees. The cocoa beans are removed from the
pods and from there the cocoa is extracted from the beans. Below is a simplified diagram of the process.
Image reproduced with permission from Nevastane & TOTAL
Question 9.
One cocoa pod weighs, on average, 400 g. An average pod will yield about 40 dried beans after roasting. In order to make
one kilogram of chocolate, you need about 880 dried beans. Approximately what mass of cocoa pods will be needed to make
one kilogram of chocolate?
A.
22 g
B.
8.8 kg
C.
22 kg
D.
88 kg
Question 10.
There are many varieties of chocolate. Some are shown below.
Type of Chocolate
Cocoa
Butter
Cocoa
Solids
Milk
Solids
Description
White chocolate
≥ 20%
0%
≥14%
Milk chocolate
≥15%
≥25%
≥12%
Sweet baking
chocolate
≥18%
≥31%
<12%
Dark chocolate
≥18%
≥35%
<5%
Off-white in colour, added sugar and vanilla give it a
mild taste
A sweet tasting chocolate that generally has added
sugar and is rarely used for baking
Darker than milk chocolate, this chocolate has
sugar added and is used for baking
With little sugar, it tends to become more bitter as
the total of percentage of cocoa increases
Which of the following statements is TRUE?
A.
B.
C.
D.
The darkness of a type of chocolate is related to the amount of cocoa butter it contains.
Chocolate becomes more bitter as the amount of cocoa butter increases.
As the total amount of cocoa in chocolate increases, so does the milk solids.
The bitterness of chocolate depends on the total amount of both cocoa and sugar.
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ANCQ 2016 YEARS 7 & 8
Question 11.
Metal compounds can sometimes have characteristic colours, as shown in the table.
Metal in the compound
Some common colours of these compounds
Manganese
Copper
Iron
Vanadium
Pale pink, blackish-brown
Blue, green
Light green, orange/red/brown
Green, orange, yellow, blue
Animals use blood to transport oxygen around their bodies, using metal compounds to help carry the oxygen.
The following table describes the blood of a number of different animals.
Animal
Humans
Spiders
Sea Squirts
The Pinna Squamosa
mollusc
Blood
colours
Dark red to
bright red
Blue to clear and
colourless
Apple green, becoming
more blue or orange
Brown
Which metal compounds can be found in the blood of each animal?
A.
B.
C.
D.
Humans
Spiders
Sea Squirts
iron
manganese
iron
iron
copper
copper
copper
vanadium
manganese
vanadium
vanadium
copper
The Pinna Squamosa
mollusc
vanadium
iron
manganese
manganese
Question 12.
th
Nitrogen is the 30 most abundant element on Earth, yet nitrogen gas, N2, is the most abundant gas in the atmosphere (78%). It is
a vital element in living things, being a component of such molecules as DNA, proteins and amino acids. The diagram shows the
Nitrogen Cycle in nature.
Image reproduced with permission from Raeky/Wikipedia
Which of the following statements is TRUE, based on the above information?
A.
B.
C.
D.
Plants get the nitrogen they need from breathing in air.
Atmospheric nitrogen is produced by nitrogen-fixing bacteria.
Nitrification is the process where bacteria produce ammonium.
Rabbits can only get the nitrogen they need by consuming plants.
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ANCQ 2016 YEARS 7 & 8
Information for Questions 13 & 14
The Nobel Prize in Chemistry for 2015 was awarded to three scientists, Tomas Lindahl, Paul Modrich and Aziz Sancar. They
each studied properties of deoxyribonucleic acid, DNA, sometimes called the “molecule of life”. This molecule contains the genetic
material in the cell of each living thing. In order to make new cells, the DNA molecule needs to be copied exactly.
Nobel Scientist
Tomas Lindahl
Paul Modrich
Aziz Sancar
Discovery
Firstly he discovered that, on its own, the DNA molecule decays, or breaks down, much quicker than expected.
However, he then discovered that our cells have molecular machinery to stop DNA from breaking down.
When our DNA is copied to make new cells, mistakes in the molecule can be made. He discovered how cells
repair the vast majority of these mistakes.
DNA can be damaged by ultraviolet (UV) radiation. He showed how cells fix this damage caused by UV
radiation.
Question 13.
Which of the following statements is TRUE, based on the information above?
A.
B.
C.
D.
Changes in the DNA molecule can occur naturally.
UV radiation stops DNA from being copied by cells.
When DNA is copied, the acid eats away at the cell.
When DNA breaks down, it produces UV radiation.
Question 14.
DNA has a double-helix structure, that is it looks like a ladder that has been twisted.
Which of the following shows the correct three-dimensional shape of DNA?
A.
B.
C.
D.
Information for Questions 15 & 16
Below are some substances and some of their properties.
Substance
Copper shavings
Sand
Table salt
Copper(II) sulfate
Styrofoam balls
Magnetic?
No
No
No
No
No
Mixed with water?
Sinks
Sinks
Dissolves
Dissolves
Floats
Conducts electricity?
Yes
No
No
No
No
A student had a small mixture of copper shavings, sand, salt and Styrofoam balls in Beaker 1. The student used the following
steps to separate a small sample of the mixture.
Step I. Swirl a magnet around the mixture and place any substances that stick to the magnet in Beaker 2.
Step II. Half fill Beaker 1 with water and stir.
Step III. Using a tea strainer (small sieve), scoop up any substance floating on the water and place in Beaker 3.
Step IV. Filter the mixture. Place the filter paper, with any substance, on a watch glass to dry.
Step V. Collect anything that went through the filter paper in Beaker 4.
Question 15.
What was collected and placed in Beaker 2 after completing Step I?
A.
C.
Sand
Copper shavings
B.
D.
Sand and copper shavings
Nothing.
Question 16.
What was collected in Beaker 4 after Step V?
A.
Salt only
B.
Salt and copper sulfate only
C.
Sand only
D.
Salt water only
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ANCQ 2016 YEARS 7 & 8
Question 17.
When 5.1 litres of water vapour at 100 C were cooled to room temperature, it condensed to form 3.0 mL of liquid water, which had
a mass of 3.0 grams.
Which statement about the water is most likely to be TRUE?
A.
B.
C.
D.
Water vapour is weightless, but gets mass when it condenses to liquid.
When the water vapour condenses, the molecules move close together.
The mass of the water vapour was 5.1 kilograms.
There are more molecules in the 5.1 litres of water vapour than in the 3.0 grams of liquid water.
Information for Questions 18 & 19
Solubility (g/L)
Solubility is a measure of how much of a substance will dissolve in a liquid, such as table salt in water. The graph shows how
changing temperature affects the solubility in water of three different substances.
60
Substance 1
Substance 2
40
20
Substance 3
0
0
20
40
60
80
Temperature (C)
100
Question 18.
Which of the following statements is TRUE?
A.
B.
C.
D.
For Substance 1, as temperature increases, solubility decreases.
About twice as much of Substance 2 will dissolve at 70 C than will dissolve at 0 C.
At 20 C, about twice as much of Substance 1 will dissolve compared to Substance 3.
More of Substance 3 will dissolve at 60 C than of Substance 1 at 20 C.
Question 19.
A sample of Substance 2 (40.0 g) was placed in 1000 mL of water. The solution was heated and stirred until all of the solid had
dissolved. The solution was then cooled down to 20 C. At this stage some of the solid had recrystallised out of solution.
Approximately what mass of Substance 2 recrystallised?
A.
10 g
B.
20 g
C.
30 g
D.
35 g
Question 20.
The chemicals in food include proteins, carbohydrates and water. Proteins can be found in meat and animal products, such as milk
and eggs. The carbohydrates group includes the simple sugars (like glucose and sucrose), starch and cellulose. Wheat, potatoes
and rice are all sources of starch. Honey contains fructose and glucose. A student tested four foods labelled J, K, L and M.
Food
J
K
L
M
Protein test
No
No
Yes
No
Glucose test
No
Yes
No
No
Starch test
No
No
No
Yes
Water content
95%
15%
35%
35%
The foods tested were bread, cheese, honey and lettuce. Which were the correct labels for the different foods?
A.
B.
C.
D.
Bread
M
M
L
J
Cheese
K
L
M
K
Honey
L
K
K
L
Lettuce
J
J
J
M
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ANCQ 2016 YEARS 7 & 8
Information for Questions 21, 22 & 23
Below is a table that compares the relative masses of some molecules. That is, how much heavier these molecules are
compared to a hydrogen (H) atom (= 1).
Molecule
Relative mass
H2
2
H2O
18
CO
28
N2
28
O2
32
CO2
44
SO2
64
Question 21.
One sulfur dioxide (SO2) molecule is
A.
C.
heavier than two carbon dioxide (CO2) molecules.
heavier than 35 hydrogen (H2) molecules.
B.
D.
lighter than four water (H2O) molecules.
lighter than two oxygen (O2) molecules.
Question 22.
Using the data in the table, the relative mass of ammonia (NH3) is
A.
12.
B.
14.
C.
15.
D.
17.
Question 23.
Avogadro’s Law of Gases says that one litre of a gas, at the same temperature and pressure, will contain the same number of
molecules as one litre of any other gas. For example, one litre of hydrogen gas contains the same number of molecules as one litre
of oxygen gas. However, because each oxygen molecule (relative mass = 32) has a greater mass than each hydrogen molecule
(relative mass = 2), one litre of oxygen gas has a mass that is 16 times more than one litre of hydrogen gas.
Which of the following is TRUE, based on Avogadro’s Law for Gases at the same temperature and pressure?
A.
B.
C.
D.
One litre of carbon monoxide (CO) molecules has the same mass as one litre of nitrogen (N2) molecules.
One litre of nitrogen (N2) molecules has a greater mass as one litre of oxygen (O2) molecules.
One litre of water vapour (H2O) has the same mass as ten litres of hydrogen (H2) molecules.
One litre of carbon monoxide (CO) molecules has a greater mass as one litre of carbon dioxide (CO2) molecules.
Question 24.
A student has four solid pure substances, W, X, Y and Z, in four separate beakers. The student is told that, in no particular order,
the substances are sugar, table salt, bicarb soda (sodium hydrogen carbonate) and magnesium metal. The student then carries out
some tests and observations. The results are recorded in the table.
Substance
W
X
Y
Z
Colour
White
White
Silver
White
Dissolves in water?
Yes
Yes
A slight reaction
Yes
Reacts with dilute acid?
Yes, bubbles form
No
Yes, bubbles form
No
Burns in air?
No
Yes, charred and smelled like toffee
Yes, and made a bright light
No
Which of the following statements is TRUE?
A.
B.
C.
D.
Substance W is magnesium and Z is table salt.
Substance W is sugar and Y is magnesium.
Substance W is magnesium and X is sugar.
Substance X is sugar and Y is magnesium.
Question 25.
The density of water at 25 C is 1.0 g/mL. The density of ice (at 0 C) is 0.92 g/mL, which is why ice floats on liquid water.
Which of the following has the greatest mass? (Assume that the water is at 25 C and the ice is at 0 C).
A.
B.
C.
D.
200 mL of water and 100 mL of ice
150 mL of water and 150 mL of ice
50 mL of water and 250 mL of ice
100 mL of water and 200 mL of ice
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ANCQ 2016 YEARS 7 & 8
Information for Questions 26 & 27
Ethanol can be produced by two methods: one starting with sugar cane, the other with crude oil, which is a mixture of organic
molecules, such as petrol and kerosene, with a wide range of boiling points.
Each method can be represented by a separate flow diagram:
Method 1:
Sugar cane
P

glucose
Q

ethanol/water mixture
R

ethanol
Method 2:
Crude oil
S

alkane mixture
T

ethene
U

ethanol
Question 26.
Each letter, P, Q, R, S, T and U, represents a process or combination of processes, including chemical and physical changes.
Fermentation is a biochemical process used to make alcoholic drinks like beer and wine. In this chemical reaction, simple sugars
are transformed into ethanol.
Which step uses fermentation?
A.
P
B.
Q
C.
T
D.
U
Question 27.
Two of the important molecules in Method 2 are shown below.
Ethanol
Ethene (also known as ethylene)
In Process U, one molecule of ethene reacts with reactant X to produce one molecule of ethanol.
Reactant X is
A.
C.
one molecule of water, H2O
one molecule of oxygen, O2
B.
D.
one molecule of hydrogen, H2
one hydroxide ion, OH
Information for Questions 28, 29 & 30
Sometimes a chemical reaction has the exact amounts of materials that react. However, usually one reactant is used up before the
other one. The one that is used up first is called the limiting reagent because it limits how much product can be made.
Question 28.
The diagram shows a reaction between two substances X2 and XY2 producing X3Y and Y2.
What is the limiting reagent in this reaction, that is, which reactant is completely used up?
A.
X2
B.
XY2
C.
X3Y
D.
Y2
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ANCQ 2016 YEARS 7 & 8
Question 29.
Oxygen gas and hydrogen gas react to form water, as described in the following word equation:
hydrogen gas + oxygen gas
 water vapour
In one experiment, 20 litres of hydrogen gas reacted with 5 litres of oxygen gas, all at room temperature. After the mixture was
reacted and cooled down to room temperature, so that all of the water condensed (negligible volume), there were 10 litres of
hydrogen gas left after the reaction.

+
20 litres of
hydrogen
+
5 litres of
oxygen
Condensed water
10 litres of
hydrogen
The experiment was repeated but using 20 litres of hydrogen gas and 20 litres of oxygen gas. This time, only 10 litres of oxygen
gas were left after the reaction.

+
20 litres of
hydrogen
+
20 litres of
oxygen
Condensed water
10 litres of
oxygen
The experiment was repeated with 10 litres of hydrogen gas, so that only water remained at the end.
+

?
10 litres of
hydrogen
? litres of
oxygen
Condensed water
What volume of oxygen gas was needed react exactly with 10 litres of hydrogen gas?
A. 5 litres
B.
6 litres
C.
10 litres
D.
15 litres
Question 30.
Beaker 1 contained a solution of potassium iodide and Beaker 2 contained a solution of lead nitrate. Each solution was added to
Beaker 3 and a bright yellow lead iodide precipitate (solid) was formed, as well as some solution remaining. The contents of
Beaker 3, including the lead iodide precipitate, were filtered, with a clear solution collected in Beaker 4.

+
Beaker 1 –
potassium iodide
Beaker 2 –
lead nitrate

Beaker 3 with lead
iodide precipitate
filtered
Beaker 4
To Beaker 4, two drops of potassium iodide solution was added and again a yellow precipitate formed.

+
Beaker 4
2 drops of
potassium iodide
yellow precipitate
Before adding any drops, Beaker 4 must have
A.
C.
contained some potassium iodide.
contained some lead nitrate.
B.
D.
only contained water.
only contained potassium iodide.
Questions compiled & typeset by Andrew Eaton, Wollondilly Anglican College, NSW, with thanks for advice and assistance from Susan Margan, Martin
Sormus, Adrian George, Tanweer Qadri and Regina Menz, NSW; and Jenny Sharwood and Roger Stapleford, Vic.
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ANCQ 2016 YEARS 7 & 8
Page can be used for rough workings
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