Download C3 Revision Question Booklet

Barnard Castle School
Chemistry Department
GCSE Chemistry
C3 Revision
Questions
Name …………………………………..
Teacher ……………………………
Barnard Castle School
1
1.
Use the periodic table on the Data Sheet to help you to answer these questions.
(a)
Write the symbol for helium.
.....................................................................................................................................
(1)
(b)
Write the name of an element in Group 4.
.....................................................................................................................................
(1)
(c)
Write the name of the element which has a relative atomic mass of 64.
.....................................................................................................................................
(1)
(d)
Write the name of the element with the next highest atomic number after Te (tellurium) in
the periodic table.
.....................................................................................................................................
(1)
(Total 4 marks)
2.
The periodic table on the Data Sheet may help you to answer this question.
(a)
Newlands and Mendeleev both designed periodic tables in which the elements were put in
the order of their relative atomic masses.
When the elements are put in this order a few of them are placed incorrectly when
compared with a modern periodic table.
(i)
Give one example of a pair of elements that would be placed incorrectly if they
were in the order of their relative atomic masses.
......................................................... and ..........................................................
(1)
(ii)
Explain why placing these two elements in the order of their relative atomic masses
would not be correct.
...........................................................................................................................
...........................................................................................................................
(1)
(b)
In the modern periodic table the elements are put in order of their atomic (proton)
numbers.
Explain how the positions of the elements in the periodic table are linked to the electronic
structure of their atoms.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 4 marks)
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2
3.
Chemical tests can be used to identify compounds.
(a)
List A gives the names of four compounds in solution. List B gives tests and the result of
the tests.
Draw a straight line from each compound in List A to its test and test result in List B. The
first one has been done for you.
List A
Name of compound
in solution
List B
Test and result of the test
Calcium chloride
Add barium chloride solution
and dilute hydrochloric acid.
A white precipitate formed.
Lithium sulphate
Do the flame test.
Yellow flame produced.
Potassium carbonate
Add silver nitrate solution and
dilute nitric acid.
A white precipitate formed.
Sodium nitrate
Add hydrochloric acid.
Carbon dioxide gas given off.
(2)
(b)
State what you would see when sodium hydroxide solution reacts with copper sulphate
solution.
....................................................................................................................................
....................................................................................................................................
(2)
(c)
(i)
Name one instrumental method which can be used to help in the identification
of substances.
...........................................................................................................................
(1)
(ii)
Suggest one advantage of the instrumental method you have named.
...........................................................................................................................
(1)
(Total 6 marks)
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3
4.
A student carried out a titration to find the concentration of a solution of hydrochloric acid. The
following paragraph was taken from the student’s notebook.
I filled a burette with hydrochloric acid. 25.0 cm3 of 0.40 mol/dm3 potassium hydroxide
was added to a flask. 5 drops of indicator were added. I added the acid to the flask until
the indicator changed colour. The volume of acid used was 35.0 cm3.
(a)
What piece of apparatus would be used to measure 25.0 cm3 of the potassium hydroxide
solution?
.....................................................................................................................................
(1)
(b)
Name a suitable indicator that could be used.
.....................................................................................................................................
(1)
(c)
Calculate the number of moles of potassium hydroxide used.
.....................................................................................................................................
.....................................................................................................................................
Moles of potassium hydroxide = ............................................ mol
(2)
(d)
Calculate the concentration of the hydrochloric acid. The equation for the reaction is:
KOH + HCl  KCl + H2O
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Concentration of hydrochloric acid = ........................................ mol/dm3
(2)
(Total 6 marks)
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4
5.
A chemist used a titration to investigate a solution used to unblock drains.
AQ
A ‘X
’
LIQUID
DRAIN
OPENER
tough on blocks
25 cm3 of a diluted solution of Drain Opener was put into a beaker. The graph shows how the
pH of this solution changed as hydrochloric acid was slowly added.
14
13
12
11
10
9
8
pH
7
6
5
4
3
2
1
0
0
(a)
5
10
15
20
25
30
35
Volume of hydrochloric acid in cm 3
40
45
What volume of hydrochloric acid was needed to neutralise the Drain Opener solution?
Volume = ...............................................cm3
(1)
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5
(b)
Which of the following best describes Drain Opener solution?
Draw a ring around your answer.
neutral
strong acid
strong alkali
weak acid
weak alkali
(1)
(c)
Which of the following would be best for accurately measuring the volume of
hydrochloric acid added?
Draw a ring around your answer.
beaker
burette
measuring cylinder
pipette
Give a reason for your choice.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 4 marks)
6.
The diagram shows some of the elements in Groups I and 7 of the Periodic Table.
0
Group
1
2
3
4
5
6
7
Li
F
Na
Cl
K
Br
I
(a)
The elements in Group 1 have similar chemical properties.
Describe one chemical reaction which shows that lithium, sodium and potassium react in
the same sort of way.
You should say what you would react them with and what substances would be produced.

What you would react them with
..........................................................................................................................

Substances produced
..........................................................................................................................
..........................................................................................................................
(3)
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6
(b)
All the elements in Group 7 react with hydrogen.
Fluorine reacts in the dark, explosively, at very low temperatures.
Chlorine reacts explosively in sunlight, at room temperature.
Bromine, in light, only reacts if heated to about 200°C.
Suggest the conditions needed for hydrogen and iodine to react.
Give reasons for your answer.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(c)
Hydrogen and chlorine react to produce hydrogen chloride.
Balance the symbol equation for the reaction.
H2
+
Cl2

HCl
(1)
(d)
Use your understanding of atomic structure to explain the trend in reactivity in the
Group 7 elements.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 8 marks)
7.
(a)
A student had forgotten to label which of two test tubes contained a solution of aluminium
nitrate.
Describe a chemical test using sodium hydroxide solution to show which test tube
contained nitrate ions. Give the result of this test.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(b)
Name an instrumental method of analysis that might be used to detect a drug in the urine
of an athelete.
.....................................................................................................................................
(1)
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7
(c)
Describe how advances in technology have assisted in the development of instrumental
methods for the detection and identification of elements and compounds.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 6 marks)
8.
A student wanted to find out how much of a substance, to the nearest 0.1 gram, dissolves in
15cm³ of water. His plan for the experiment is shown below, but the descriptions of some of the
steps have been missed out.
1 Grind the substance in a pestle and mortar.
2
3
4 Add the 0.1 gram of the substance to the water in the test tube.
5
YES
6 Examine to see if all the substance is dissolved.
NO
7
The missing steps in his plan are written below, but not in the correct order.
(a)
A
Shake thoroughly for some time.
B
Measure out 0.1 gram of the substance.
C
Record the amount of substance added.
D
Measure out 15cm³ of water into a test tube.
Write the letters A, B, C and D in the boxes in his plan, in the correct order.
(4)
(b)
How would you know that the substance had dissolved?
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 6 marks)
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8
9.
Many soft drinks contain citric acid.
INGREDIENTS: CARBONATED
WATER, SUGAR, CITRIC ACID,
ACIDITY REGULATOR (E331),
FLAVOURINGS,
PRESERVATIVE (E211)
(a)
Citric acid is a weak acid.
(i)
What is meant by a weak acid in terms of its ionisation in water?
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
Describe and give the results of an experiment which would show that citric acid is
a weaker acid than hydrochloric acid of the same concentration.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(b)
Citric acid behaves as an acid. Explain why, using the ideas of Arrhenius and of
Bronsted-Lowry.
To gain full marks in this question you should write your ideas in good English. Put them
into a sensible order and use the correct scientific words.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 6 marks)
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9
10.
Chemical tests are used to identify compounds.
(a)
What colour is produced by sodium compounds in flame tests?
.....................................................................................................................................
(1)
(b)
Chemical tests are carried out on these substances.
ammonium chloride
potassium nitrate
copper bromide
copper nitrate
magnesium sulphate
zinc carbonate
Complete each sentence by choosing the correct substance from the box. You may use
each substance once or not at all.
The substance which
(i)
reacts with dilute hydrochloric acid to produce carbon dioxide gas is
............................................................................................................................
(1)
(ii)
in solution reacts with sodium hydroxide solution to form a blue precipitate is
...........................................................................................................................
(1)
(iii)
in solution reacts with barium chloride solution, in the presence of dilute
hydrochloric acid, to form a white precipitate is
............................................................................................................................
(1)
(c)
State what you see when sodium chloride solution reacts with silver nitrate solution in the
presence of dilute nitric acid.
......................................................................................................................................
(1)
(Total 5 marks)
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10
11.
A leaflet listed the effects of hard water:
HOW HARD WATER COSTS YOU HARD CASH
Hard water causes:
 Blocked showers, burnt out immersion heaters
 Scale build up inside water pipes
 Higher water heating cost
 Extra soap required to get a lather
Describe how softening the hard water could save money.
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
(3)
(Total 3 marks)
12.
One definition of an element is:
“A substance that cannot be broken down into simpler substances by chemical methods.”
The table shows some of the “substances” which Antoine Lavoisier thought were elements. He
divided the “substances” into four groups. He published these groups in 1789.
The modem names of some of the “substances” are given in brackets.
Acid-making
elements
Gas-like
elements
Metallic
elements
Earthly
elements
sulphur
light
cobalt
mercury
lime
(calcium oxide)
magnesia
(magnesium oxide)
phosphorus
caloric
(heat)
copper
nickel
charcoal
(carbon)
oxygen
gold
azote
(nitrogen)
iron
platina
(platinum)
silver
barytes
(barium sulphate)
argilla
(aluminium oxide)
hydrogen
lead
tin
silex
(silicon dioxide)
manganese tungsten
zinc
(a)
Name one “substance” in the list which is not a chemical element or compound.
.....................................................................................................................................
(1)
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11
(b)
Name one “substance” in the list which is a compound.
(i)
..........................................................................................................................
(1)
Suggest why Lavoisier thought that this “substance” was an element.
(ii)
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(1)
(c)
Dimitri Mendeleev devised a Periodic Table of the elements in 1869. A modem version of
this table is shown on the Data Sheet.
Give two ways in which Mendeleev’s table is more useful than Lavoisier’s.
1 .................................................................................................................................
.....................................................................................................................................
2 .................................................................................................................................
.....................................................................................................................................
(2)
(Total 5 marks)
13.
(a)
Complete each sentence about water by choosing the correct words from the box. Each
word may be used once or not at all.
calcium
(i)
chloride
chlorine
hydroxide
nitrate
oxygen
Hardness in water is caused by dissolved ........................................ ions.
(1)
(ii)
Some ........................................ dissolved in water is essential for aquatic life.
(1)
(iii)
The use of artificial fertilisers can result in many natural waters being
contaminated with dissolved ........................................ ions, which can have
harmful effects on babies.
(1)
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12
(b)
The diagram shows part of the water cycle.
Wind
Cloud
Sun
Rain
Lake
Sea
River
Describe what is happening in the water cycle.
To gain full marks you should write down your ideas in good English. Put them into a
sensible order and use correct scientific words.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(3)
(c)
This label has been taken from a bottle of carbonated mineral water.
Sparkling Mineral Water
MINERAL ANALYSIS
TYPICAL VALUES mg/l
Calcium
35.0
Magnesium
5.3
Sodium
22.0
Potassium
2.2
Chloride
38.0
Sulphate
22.0
Nitrate
Fluoride
Carbonated Natural Mineral Water
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34.0
LESS THAN 0.1
2 LITRE
e
13
(i)
The bar chart shows the amounts of some of the ions in this mineral water.
40
30
Amount
of ions in 20
mg per litre
10
0
Calcium
Sodium
Chloride
Sulphate
Nitrate
Complete the bar chart to show the amount of nitrate ions given on the label.
(1)
(ii)
Describe how water is carbonated.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 9 marks)
14.
The idea of a periodic table of the elements was started by John Newlands about 140 years ago.
He wrote down the elements he knew about in order, starting with the lightest atoms.
Then he arranged them into seven groups, like this:
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1
2
3
4
5
6
7
H
Li
Be
B
C
N
O
F
Na
Mg
Al
Si
P
S
Cl
K
Ca
14
(a)
Write down three differences between the groups in Newlands’ periodic table and the
groups in the modern periodic table (up to the element Ca, which is calcium).
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(b)
Suggest one reason why this part of Newlands’ table was different from the modern one.
.....................................................................................................................................
.....................................................................................................................................
(1)
(c)
Dimitri Mendeléev later developed the periodic table of the elements. He arranged the
elements according to their properties and their relative atomic masses.
The diagram shows where Mendeléev put tellurium (Te) and iodine (I) in his table
because of their properties.
(The diagram uses present day symbols and the atomic numbers of the elements have been
added to Mendeléev’s table.)
GROUP 6
GROUP 7
16
O
8
19
F
9
32
S
16
35.5
Cl
17
80
Br
35
128
Te
52
(i)
127
I
53
What is wrong with this arrangement of tellurium and iodine in terms of their
relative atomic masses?
...........................................................................................................................
...........................................................................................................................
(1)
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15
(ii)
Explain why this is not a problem in the modern periodic table.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 7 marks)
15.
The table shows some properties of four Group 7 elements.
Element
Reaction with hydrogen
Boiling
point in ºC
Melting
point in ºC
State at room
temperature
Fluorine
– 218
– 188
Chlorine
– 34
– 101
Bromine
+ 59
–7
Reacts if heated
Iodine
+ 185
+ 114
Reacts if heated
strongly
(a)
Description
Product
gas
Explosive reaction
in dim light
Hydrogen
fluoride
gas
Explosive reaction in
sunlight
Hydrogen
chloride
Hydrogen
iodide
What is the state at room temperature of:
(i)
bromine; ...............................................
(ii)
iodine? ..................................................
(2)
(b)
Which one of the four elements is most reactive?
.....................................................................................................................................
(1)
(c)
Name the compound formed when hydrogen reacts with bromine.
.....................................................................................................................................
(1)
(Total 4 marks)
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16
16.
The symbol equation shows the reaction between methane and oxygen.
CH4
methane
+

2O2
oxygen
CO2 +
carbon dioxide
2H2O
water
The structural formulae in the equation below show the bonds in each molecule involved.
H
H
C
H
+ 2 [O = O]
O = C = O + 2 [H – O – H]
H
In the three stages shown at (i), (ii) and (iii) below, calculate the net energy transfer when the
formula mass (1 mole) of methane reacts with oxygen.
(i)
Write down the bonds broken and the bonds formed during the reaction.
Bonds broken
Bonds formed
number
number
type
type
(4)
(ii)
Calculate the total energy changes involved in breaking and in forming each of these
bonds.
Total energy change in
breaking bonds
Total energy change in
forming bonds
(4)
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17
(iii)
Describe, as fully as you can, what the above figures in (ii) tell you about the overall
reaction.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 10 marks)
17.
Rainwater falling on limestone rocks can form caves.
Rain
Limestone
Cave
Lake
(a)
Complete the sentences by choosing the correct words from the box.
acidic
hard
alkaline
reacts
dissolves
soft
tastes
You may use each word once or not at all.
Rainwater is an ....................... solution which ....................... with limestone. The
solution formed in the lake is known as ....................... water. One advantage of
drinking the water from the lake is that it ....................... better than rainwater.
(4)
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18
(b)
Samples of water were tested by shaking with soap solution. The results are shown in the
table.
Water sample (50 cm3)
(i)
Volume of soap solution to
form a lather in cm3
lake
15
boiled lake
3
rain
1
What is seen when only 10 cm3 of soap solution is shaken with 50 cm3 of water
from the lake?
...........................................................................................................................
(1)
(ii)
Why did the rainwater need only 1 cm3 of soap solution to form a lather?
...........................................................................................................................
(1)
(iii)
Why did the water from the lake need 15 cm3 of soap solution to form a lather?
...........................................................................................................................
(1)
(iv)
Explain why boiled water from the lake needed only 3 cm3 of soap solution to form
a lather.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 9 marks)
18.
(a)
The diagram shows the electronic structure of a particular element.
x
x
x
x
In a similar way, show the electronic structure of another element from the same group in
the periodic table and name the element you select.
Name of element selected ..........................................................................................
(4)
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19
(b)
The element lithium gives a moderate reaction with cold water, releasing hydrogen and
forming a solution of lithium hydroxide.
Describe how sodium is similar to and how it is different from lithium in its chemical
reaction with cold water.
Explain any similarity or difference in terms of their atomic structure.
Similarity. ..................................................................................................................
Reason. ......................................................................................................................
....................................................................................................................................
....................................................................................................................................
Difference. .................................................................................................................
Reason. ......................................................................................................................
....................................................................................................................................
....................................................................................................................................
(5)
Total 9 marks)
19.
Four labels have come off four bottles.
Aluminium sulfate
solution
Ammonium sulfate
solution
Al2(SO4)3(aq)
(NH4)2SO4(aq)
Magnesium sulfate
solution
Sodium sulfate
solution
MgSO4(aq)
Na2SO4(aq)
Describe and give the results of the chemical tests that you would do to identify which bottle
contained which substance.
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
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20
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
(Total 6 marks)
20.
Chemical tests can be used to identify compounds.
The table shows the results of some tests carried out on three solutions, A, B and C.
Solution
Flame Test
A
Yellow
B
Brick-red
C
Hydrochloric
acid
is added
Sodium
hydroxide
solution
is added
Silver nitrate
solution
is added
Carbon dioxide
gas produced
White precipitate
insoluble in
excess sodium
hydroxide
solution
White
precipitate
Dark green
precipitate
Use the information in the table to identify solutions A, B and C.
Give the name of:
(a)
solution A; ...................................................................................................................
(2)
(b)
solution B; ...................................................................................................................
(2)
(c)
the metal ion in solution C. .........................................................................................
(1)
(Total 5 marks)
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21
21.
The diagram shows a simplified flow diagram of a water treatment works which supplies
drinking water.
Water from
reservoir
Simplified flow diagram
of water treatment
Filtration
Sampling
Chlorination
and stabilisation
To homes
Storage
(a)
Explain the purpose of:
(i)
filtration
...........................................................................................................................
...........................................................................................................................
(ii)
chlorination.
...........................................................................................................................
...........................................................................................................................
(2)
(b)
Samples of the treated water must be tested at regular intervals.
(i)
Suggest why.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(ii)
Suggest how the use of ICT and/or data logging equipment could help with this
testing.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(c)
Drinking water can also be produced using distillation.
Explain why this process is expensive.
.....................................................................................................................................
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22
.....................................................................................................................................
(1)
(d)
In some parts of the country the water supplied to homes is hard water.
(i)
Name one ion that can make water hard.
...........................................................................................................................
(1)
(ii)
Explain how hard water can affect central heating systems.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(iii)
State one advantage of hard water.
...........................................................................................................................
(1)
(Total 11 marks)
22.
Washing powders are a mixture of substances. The substances in a box of Kleenkwik washing
powder are shown.
Detergent
Bleach
Perfume
Soap
Sodium phosphate
Supersoap
(a)
Which substance in the washing powder gives clothes a pleasant smell?
....................................................................................................................................
(1)
(b)
What does a bleach do?
....................................................................................................................................
(1)
(c)
Sodium phosphate removes the hardness in water.
(i)
What is hard water?
.........................................................................................................................
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23
.........................................................................................................................
(1)
(ii)
Why should the hardness be removed?
.........................................................................................................................
.........................................................................................................................
(1)
(iii)
Give another method which removes the hardness in water.
.........................................................................................................................
.........................................................................................................................
(1)
(d)
Circle the chemical which is used to make detergents.
carbonic acid
hydrochloric acid
sulphuric acid
(1)
(Total 6 marks)
23.
The symbol equation shows the decomposition of water.
2H2O

2H2
+
O2
An energy level diagram for this reaction is shown below.
energy
(kJ)
x
(1856 kJ)
y
(1370 kJ)
hydrogen + oxygen
(products)
z
water
(reactant)
Explain the significance of x, y and z on the energy level diagram in terms of energy transfers
that occur in the reaction. You should make specific reference to the bonds broken and formed
and to the nett energy transfer (energy transferred to or from the surroundings).
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
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24
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
(Total 6 marks)
24.
A sample of water taken from a lake was found to contain sulphuric acid.
A student carried out a titration to find the concentration of the sulphuric acid in this sample.
25.0 cm3 of the sulphuric acid solution was neutralised exactly by 34.0 cm3 of a potassium
hydroxide solution of concentration 0.2 mol dm–3. The equation for the reaction is:
2KOH(aq) + H2SO4(aq)  K2SO4(aq) + 2H2O(1)
(a)
Describe the experimental procedure for the titration carried out by the student.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(4)
(b)
Calculate the number of moles of potassium hydroxide used.
.....................................................................................................................................
Number of moles = ...........................
(2)
(c)
Calculate the concentration of the sulphuric acid in mole per cubic decimetre (mol dm–3).
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Concentration = .................. mol dm–3
(3)
(Total 9 marks)
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25
25.
The label shows the ions present in the bottle of spring water. This water is temporarily hard.
Composition mg/litre
calcium Ca2+
magnesium Mg 2+
potassium K +
SPRING
WATER
WITH
FIZZ
(a)
sodium Na+
–
chloride Cl
–
fluoride F
nitrate NO3 –
sulphate SO4 2–
hydrogencarbonate HCO 3 –
35
15
1
12
10
1
2
6
179
Name the compound that would be present in the greatest amount if this water were
evaporated to dryness.
.....................................................................................................................................
(2)
(b)
(i)
What is hard water?
...........................................................................................................................
...........................................................................................................................
(2)
(ii)
State one advantage of hard water.
...........................................................................................................................
(1)
(c)
Describe an experiment that would show that this water is temporarily hard.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(4)
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(d)
This hard water may be softened as shown.
2+
Ca and Mg
in water
2+
Ca 2+ and Mg2+
in solid
Na +
on solid
Na +
in water
Before
After
What name is given to this process?
.....................................................................................................................................
(1)
(Total 10 marks)
26.
(a)
This label has been taken from a bottle of vinegar.
es or preserva
dditiv
tive
a
s
no
MALT
VINEGAR
Pur
eM
r
alt Vinega
Vinegar is used for seasoning foods. It is a solution of ethanoic acid in water.
In an experiment, it was found that the ethanoic acid present in a 15.000 cm3.sample of
vinegar was neutralised by 45.000cm3 of sodium hydroxide solution, of concentration
0.20 moles per cubic decimetre (moles per litre).
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The equation which represents this reaction is
CH3COOH + NaOH 
CH3COONa + H2O
Calculate the concentration of the ethanoic acid in this vinegar:
(i)
in moles per cubic decimetre (moles per litre);
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
Concentration =................................... moles per cubic decimetre
(2)
(ii)
in grams per cubic decimetre (grams per litre).
Relative atomic masses: H = 1; C = 12; O = 16.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
Concentration = .................................. grams per cubic decimetre
(2)
(b)
The flow diagram shows some reactions of ethanoic acid.
Sodium ethanoate + water
Alkali B
Sodium ethanoate
+
Ester C
Sodium
Ethanoic acid
Ethanol +
catalyst D
gas A
+
water
Sodium carbonate
Carboxylic acid salt E + water + carbon dioxide
Give the name of:
(i)
gas A,
............................................................................................................................
(1)
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(ii)
alkali B,
............................................................................................................................
(1)
(iii)
ester C,
............................................................................................................................
(1)
(iv)
catalyst D,
............................................................................................................................
(1)
(v)
carboxylic acid salt E.
............................................................................................................................
(1)
(Total 9 marks)
27.
The symbol equation below shows the reaction when methane burns in oxygen.
CH4 + 2O2  CO2 + 2H2O
An energy level diagram for this reaction is shown below.
x
Energy
level
methane +
oxygen
(reactants)
y
z
carbon dioxide +
(products)
water
(a)
Which chemical bonds are broken and which are formed during this reaction?
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(4)
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(b)
Explain the significance of x, y and z on the energy level diagram in terms of the energy
transfers which occur when these chemical bonds are broken and formed.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(Total 9 marks)
28.
John Newland produced a periodic table in 1866. The first 21 elements in his table are shown in
the diagram.
Column
1
2
3
4
5
6
7
H
Li
Be
B
C
N
O
F
Na
Mg
Al
Si
P
S
Cl
K
Ca
Cr
Ti
Mn
Fe
Use the periodic table on the Data Sheet to help you to answer these questions.
(a)
In which two columns of Newland’s periodic table do all the elements have similar
properties?
.....................................................................................................................................
(1)
(b)
The modern periodic table is arranged in a different order to Newland’s table.
(i)
What order is used in the modern periodic table?
...........................................................................................................................
(1)
(ii)
Argon has a higher relative atomic mass than potassium. Explain why.
...........................................................................................................................
(1)
(iii)
Describe the changes in the number of electrons in the atoms of elements in the
period which begins with potassium and ends with krypton.
...........................................................................................................................
...........................................................................................................................
(2)
(Total 5 marks)
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29.
Use the Periodic Table of Elements on the Data Sheet to help you to answer this question.
Francium (Fr) is a very rare element. It is estimated that there is only 25 g of francium in the
Earth’s crust. Francium is radioactive and has a half-life of only a few minutes.
Mendeleev predicted the existence of francium in the 1870s but the element was not discovered
until 1939.
(a)
Explain why Mendeleev was able to predict the existence of francium in the 1870s.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(b)
Suggest why there is not much experimental evidence for the properties of francium.
.....................................................................................................................................
.....................................................................................................................................
(1)
(c)
(i)
If you could react francium with water, how would the reaction compare with that
of sodium with water?
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
Explain the reason for your answer.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 6 marks)
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30.
This label has been taken from a bottle of household ammonia solution.
Smith’s Household
Ammonia Solution
Ideal for all
household
cleaning tasks!
Nothing shifts
grease like
Smith’s does!
Household ammonia is a dilute solution of ammonia in water. It is commonly used to remove
grease from ovens and windows.
(a)
The amount of ammonia in household ammonia can be found by titration.
25.0 cm3 of household ammonia is placed in a conical flask. Describe how the volume of
dilute nitric acid required to neutralise this amount of household ammonia can be found
accurately by titration. Name any other apparatus and materials used.
To gain full marks you should write down your ideas in good English. Put them into a
sensible order and use correct scientific words.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(4)
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(b)
In an experiment, it was found that 25.0 cm3 of household ammonia was neutralised by
20.0 cm3 of dilute nitric acid with a concentration of 0.25 moles per cubic decimetre.
The balanced symbol equation which represents this reaction is
NH3(aq) + HNO3(aq)  NH4NO3(aq)
Calculate the concentration of the ammonia in this household ammonia in moles per cubic
decimetre.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
Concentration = ............................. moles per cubic decimetre
(2)
(c)
The salt, ammonium nitrate, is formed in this reaction.
Describe, and give the result of, a chemical test which shows that ammonium nitrate
contains ammonium ions.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(2)
(Total 8 marks)
31.
The table shows the properties of four elements from Group VII of the Periodic Table.
Element
Proton Electronic Boiling
Melting State at
Number structure point (ºC) point (ºC) 20ºC
Fluorine
2.7
–188
–218
–34
–101
Chlorine
17
Bromine
35
2.8.18.7
+59
–7
Iodine
53
2.8.18.18.7
+185
+114
(a)
gas
Reaction with hydrogen
Ease
Product
Explosive reaction hydrogen
in dull light
fluoride
Explosive reaction hydrogen
in sunlight
chloride
solid
React if
heated
hydrogen
bromide
React if heated
strongly
hydrogen
iodide
Complete the spaces in the table.
(4)
(b)
Comment briefly on the trend in melting points for these four elements.
.....................................................................................................................................
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.....................................................................................................................................
(1)
(c)
Explain, in as much detail as you can:
(i)
why the reactions of these elements with hydrogen are similar.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(ii)
why their reactivity with hydrogen decreases from fluorine to iodine.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(4)
(Total 9 marks)
32.
This label has been taken from a packet of SuperClean.
Sodium percarbonate is a powerful stain removing chemical.
The formula of sodium percarbonate can be represented as Na2C2O6
(a)
(i)
Calculate the number of moles of sodium percarbonate in the 50 g packet.
Relative atomic masses: C = 12; O = 16; Na = 23.
...........................................................................................................................
...........................................................................................................................
Number of moles = .....................................
(2)
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(ii)
Calculate the concentration of the sodium percarbonate solution, in moles per cubic
decimetre, when 50 g of sodium percarbonate is dissolved in 6 litres (dm3) of water.
...........................................................................................................................
...........................................................................................................................
Concentration = ....................moles per cubic decimetre
(1)
(b)
When sodium percarbonate acts as a stain removing chemical, it decomposes to produce
oxygen.
The equation which represents the decomposition of sodium percarbonate is
2Na2C2O6  2Na2CO3 + 2CO2 + O2
(i)
Calculate the number of moles of oxygen produced from 50 g of sodium
percarbonate.
...........................................................................................................................
...........................................................................................................................
Number of moles = .....................................
(1)
(ii)
Calculate the volume of oxygen, at room temperature and pressure, produced from
50 g of sodium percarbonate.
1 mole of any gas at room temperature and pressure has a volume of 24 dm3.
...........................................................................................................................
...........................................................................................................................
Volume of oxygen = ............................ dm3
(2)
(Total 6 marks)
33.
Some substances dissolve in water.
The solubility of a substance is the number of grams that will dissolve in 100 grams of water.
The diagram below shows how the solubilities of two substances, potassium nitrate and sodium
chloride, vary between 0 – 100°C.
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250
potassium
nitrate
200
150
Solubility
(grams)
100
50
sodium
chloride
0
0
10
20
30
40
50
60
70
80
90
100
Temperature (°C)
(a)
How much potassium nitrate dissolves in 100 grams of water at 60°C?
........................................ grams
(1)
(b)
Describe what happens to the solubilities of potassium nitrate and sodium chloride
between 0 – 100°C.
Answer in as much detail as you can.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(5)
(Total 6 marks)
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34.
Many hydrocarbons are used as fuels. An energy level diagram is shown for the combustion of
the hydrocarbon methane.
Energy
(kJ)
CH 4 (g) + 2O 2 (g)
CO 2 (g) + 2H 2 O(I)
Describe and explain why the line rises and then falls to a lower level.
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
(Total 4 marks)
35.
(a)
Choose from the names of elements in the box the answers to the questions which follow.
aluminium
carbon
chlorine
copper
helium
iron
magnesium
sodium
Give the name of:
(i)
an alkali metal
...........................................................................................................................
(1)
(ii)
a halogen
...........................................................................................................................
(1)
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(iii)
a noble gas
...........................................................................................................................
(1)
(b)
The alkali metals are in Group 1 of the Periodic Table. The elements in Group 1 have a
number of similar properties.
(i)
Describe one chemical property which they have in common.
...........................................................................................................................
(1)
(ii)
Describe one physical property which they have in common.
...........................................................................................................................
(1)
(Total 5 marks)
36.
The balanced equation for the combustion of ethane is shown using structural formulae.
2H
(a)
H
H
C
C
H
H
C + 7O
O
4O
C
O + 6H
O
H
Complete the table to show the number of bonds broken and made when two molecules of
ethane react with seven molecules of oxygen.
Type of bond
Number of bonds
broken
Number of bonds
made
C –– C
C –– H
OO
CO
H –– O
(2)
(b)
The combustion of ethane is a strongly exothermic process. Draw a labelled energy level
diagram showing the endothermic and exothermic parts of the overall reaction. Indicate
the activation energy on the diagram.
(4)
(c)
Explain, in terms of particles and the activation energy of a reaction, how a catalyst is able
to increase the rate of reaction.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(2)
(Total 8 marks)
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37.
You will find the information on the Data Sheet helpful when answering this question.
This equation shows the reaction between ethene and oxygen.
C2H4
+
3O2

2CO2
+
2H2O
The structural formulae in the equation below show the bonds in each molecule involved.
H
H
C
C +
H
H
3 [O = O]
2[O = C = O]
+
2[H – O –H]
Use the three stages shown at (a), (b) and (c) below to calculate the nett energy transfer when the
formula mass (1 mole) of ethene reacts with oxygen.
(a)
Write down the bonds broken and the bonds formed during the reaction. (Some have
already been done for you.)
Bonds broken
Bonds formed
Number
Type
Number
Type
4
[C – H]
4
[C = O]
1
[C = C]
(2)
(b)
Calculate the total energy changes involved in breaking and in forming all of these bonds.
(Some have already been done for you.)
Total energy change in
breaking bonds
Total energy change in
forming bonds
[4 × 413] = 1652
4 × [805] = 3220
[1 × 612] = 612
Total =
Total =
kJ
kJ
(4)
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(c)
Describe, as fully as you can, what the figures in (b) tell you about the overall reaction.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 8 marks)
38.
The electronic structures of five elements, V, W, X, Y and Z are shown below.
(a)
(i)
V
W
X
Y
Z
2.1
2.6
2.8.4
2.5
2.8.6
Write the letters of the two elements which belong to the same group in the
Periodic Table ..................................................................................................
(ii)
To which group do they belong? .....................................................................
(2)
(b)
Write the letters of two elements that are gases ........................................................
(1)
(c)
Lithium, sodium and potassium are the first three elements in Group 1 of the Periodic
Table.
(i)
Lithium reacts with cold water to produce lithium hydroxide and hydrogen.
Describe how the reaction between sodium and water is
(A) similar and (B) different to that between lithium and water.
(A) Similar ........................................................................................................
...........................................................................................................................
(B) Different .....................................................................................................
...........................................................................................................................
(3)
(ii)
Potassium is much more reactive than lithium.
Explain this in terms of their electronic structures.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(3)
(Total 9 marks)
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39.
The diagram shows part of the periodic
table.
Group 0
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
23
24
27
28
31
sodium
magnesium
aluminium
silicon
phosphorous sulphur
11
12
13
14
15
32
16
Group 7
35
40
chlorine
argon
17
18
Choose from the elements shown in the table:
(a)
one metal ....................................................................................................................
(1)
(b)
a noble gas .................................................................................................................
(1)
(c)
a coloured gas ............................................................................................................
(1)
(Total 3 marks)
40.
Part of the Periodic Table is shown. It includes the symbols for six elements.
C
Li
F
Na
(a)
Ca
Ha
log
en
s
Al
ka
li m
eta
ls
K
Write the symbol for carbon. .....................................................................................
(1)
(b)
(i)
Put the symbol Cl, for chlorine, into its correct position in the Table.
(1)
(ii)
Bromine, chlorine, fluorine and iodine are halogens. Which one of these halogens is
least reactive?
...........................................................................................................................
(1)
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(c)
The alkali metals form Group 1 in the Periodic Table. Write the symbol of the most
reactive alkali metal shown in the Table above.
....................................................................................................................................
(1)
(d)
Write the symbol for an element which is in the same Group as sodium.
....................................................................................................................................
(1)
(Total 5 marks)
41.
These are the electronic structures of the atoms of three different elements.
2.8.1
element A
(a)
2.8.8
element B
2.8.8.1
element C
Identify elements A and B.
Element A is ...............................
Element B is ...............................
(2)
(b)
(i)
Why is element C more reactive than element A?
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(ii)
Why is element B unreactive?
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 6 marks)
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42.
Methane and oxygen react together to produce carbon dioxide and water.
CH 4 + 2O 2
CO 2 + 2H2 O
818 kJ of energy is given out
to the surroundings for each
formula mass (mole) of
methane that reacts.
The methane gas will not burn in oxygen until a flame is applied, but once lit it continues to
burn.
(a)
Explain why energy must be supplied to start the reaction but it continues by itself once
started.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(4)
(b)
Sketch an energy level diagram for the reaction and indicate on the diagram the nett
energy released.
Energy
Time
(3)
(Total 7 marks)
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43.
Complete the table which shows some of the physical properties of bromine, chlorine and
iodine.
Melting point Boiling point
in °C
in °C
Physical state
at 23 °C
Colour of
vapour
Bromine
–7
58
.................................
.................................
Chlorine
–101
–34
.................................
greenish
114
183
.................................
.................................
Iodine
(Total 2 marks)
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