CAMBRIDGE IGCSE™ CHEMISTRY: ENGLISH LANGUAGE SKILLS WORKBOOK
English Language
Skills answers
Chapter 1
Exercise 1.1
1
a
b
2
Physical state
Volume
Density
Shape
Fluidity
solid
has a fixed volume
high
has a definite shape
does not flow
liquid
has a fixed volume
moderate
to high
does not have a definite
shape – takes the shape
of the container
generally
flows easily
gas
does not have a fixed
volume – expands to
fill the container and
can be compressed
low
does not have a definite
shape – takes the shape
of the container
flows easily
i
ii
iii
iv
v
higher
lower
fixed; expands
fluid; more
compressed; pressure
a
Evaporation and
condensation take
place over a range
of temperatures; boiling
takes place at a specific
temperature known as
the boiling point.
freezing or
solidification
melting
liquid
Melting: a pure substance
melts suddenly at a particular
temperature.
Freezing: the reverse takes
place sharply at the same
temperature known as the
freezing point.
increasing temperature
condensation or
liquefaction
evaporation or
vaporisation
gas
solid
1
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Chapter 1 continued
b
3
Possible titles include:
Changes in physical state / The effect of
temperature on the physical state (of a
substance) / Changes in physical state
with increasing (rising) temperature
Verb
Noun – name
of process
Noun –
product of
process
to condense
condensation
condensate
to evaporate
evaporation
vapour
to crystallise
crystallisation
crystals
to precipitate
precipitation
precipitate
to solidify
solidification
solid
Exercise 1.4
8
9
Diffusion
• is the process occurring when the particles
of a substance spread and mix
• is a random process that can only take
place in fluids (liquids and gases)
• is much faster in gases
• is faster at higher temperatures.
a dilute/concentrated; dissolved/
undissolved; soluble/insoluble
b i
solution; solute; solvent
ii solute; solution; saturated
Exercise 1.2
4
5
a
b
c
d
e
a
b
so
so
because
because
which suggests that
1–D; 2–A; 3–B; 4–C
ii A word used to describe a liquid
that has a low boiling point and
evaporates easily.
iii The process which is the reverse
of melting and can also be called
solidification.
iv The process which turns a liquid into
a gas below its boiling point.
Exercise 1.3
6
7
a
b
a
b
2
random; irregular; able; can
irregular; able; collide
i
vibrate; strongly; melting point;
energy; move; melts; liquid
ii temperature; gain; faster; evaporation;
boiling point; bubbles; boils
lose energy; move around more slowly;
forces between particles; freezing point;
fixed positions; turns into a solid
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Chapter 2
Exercise 2.1
Exercise 2.2
1
2
a
molecule; element; atom; compound
b
Term
Definition
mixture
two or more chemical
substances physically
mixed together
compound
a chemical substance
made from two or more
elements chemically
bonded together
molecule
c
nucleus
proton
electron
a particle made up of more
than one atom chemically
bonded together
element
a chemical ‘building block’
of all matter that cannot
be broken down into
simpler substances
atom
the smallest particle of an
element that can take part
in a chemical reaction
a
b
c
B = element; C = mixture; D = compound
3
4
protons and neutrons; 7
The electrical charge on the nucleus is
positive because it contains protons
which are positive and neutrons that
have no charge.
d It must lose at least one electron.
The reason for this is that it will then have
more protons than electrons and so will
be positively charged.
e first shell (energy level) = 2; second shell
(energy level) = 8
x = 31
y = 15
1
2
3
4
5
6
F
E
B
A
C
D
Exercise 2.3
5
3
Order of sentence fragments: b, d, f, e, a, c, g.
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Chapter 2 continued
Exercise 2.4
6
7
tri-oxygen
a 4; 2
b 2
c i
ii
d
4
Prefix
Meaning of the prefix
Example
Explanation of example
mono-
one of something
carbon monoxide
the molecule contains one
oxygen atom
di- or bi-
two of something
diatomic
a molecule containing two atoms
tri-
three of something
sulfur trioxide
the molecule contains three
oxygen atoms
tetra-
four of something
tetrachloromethane
the molecule contains four
chlorine atoms
penta-
five of something
phosphorus
pentoxide
the molecule contains five
oxygen atoms
nitrogen dioxide; vanadium pentoxide; phosphorus trioxide
Prefix
Meaning of the prefix
Example
Explanation of example
non-
not having a particular nature
or property
non-metal
an element that is not a metal
un-
not having a particular nature
or property
unstable
a substance that breaks down
very easily
in-
not having a particular nature
or property
insoluble
a substance that is not soluble
(does not dissolve)
ir-
not having a particular nature
or property
irregular
having an arrangement that is
not organised
sub-
under or smaller than
subatomic particles
particles smaller than an atom
iso-
same
isotope
atoms of the same element with
different nucleon numbers
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Chapter 3
Exercise 3.1
Exercise 3.4
1
8
transfer; from; to; metal; lose; positive; forces;
between; opposite; sharing; between; in;
non-metals; two
2
+
3
–
H
Na
O
When an ionic bond
is made, electrons
are transferred
from one atom
to another.
A shared pair of
electrons makes a
covalent bond.
a
b
c
There are two covalent bonds between the
atoms in an oxygen molecule.
The bonds in oxygen and carbon dioxide
molecules are covalent bonds.
All the atoms in these two molecules
have a share of eight electrons in their
outer shell.
Exercise 3.2
4
a
b
c
5
a
b
c
d
9
a
b
c
d
e
f
g
h
i
j
a
b
c
d
e
conduct
transparent
shiny
appearance
slippery
tetrahedrally
three-dimensional
hexagonally
two-dimensional
layered
Both; covalent bonds; giant
but; colourless and transparent
but; is soft and slippery
but; does (conduct)
Here is an example answer: Diamond is a
very hard transparent solid that does not
conduct electricity, but graphite is a dark
grey, slippery and opaque solid that does
(conduct electricity).
10 Order of statements
1 A
2 C
3 E
4 D
5 B
6 G
7 F
are; contains; are; lost; negatively
consists; is; electrons; positive
are; consist; protons; 18; negative;
is; moves
electrostatic; hold
form; regular
attraction; are; require
Six; surround
Exercise 3.3
6
7
5
molecule; share; overlap; centre; single; eight;
stable; noble
a with; to
b in
c of; in
d to
e between
f throughout
g within/in; between
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Chapter 4
Exercise 4.1
1
2
3
6
Exercise 4.2
4
a
nucleus; electrons; protons; nuclei;
nucleus; proton
electrons; power; combining; electrons;
formula; formulae; valencies
Elements
present
Name of
compound
Formula
potassium and
bromine
potassium
bromide
KBr2
zinc and sulfur
zinc sulfide
ZnS
Exercise 4.3
barium and
chlorine
barium chloride
BaCl2
5
magnesium and
nitrogen
magnesium
nitride
sulfur and
oxygen
nitrogen and
oxygen
b
Definition
Term
Mg3N2
a change in which new
substances are produced
chemical
reaction
sulfur trioxide
SO3
the substances that react
together in a chemical reaction
reactants
nitrogen dioxide
NO2
the chemicals available in
a laboratory
reagents
the substance formed in
a chemical reaction
product
a change in which the
substances remain the same –
no new substances are formed
physical
change
Elements present
Name of
compound
Formula
sodium, hydrogen,
carbon and oxygen
sodium
hydrogen
carbonate
NaHCO3
zinc, sulfur and
oxygen
zinc sulfate
ZnSO4
magnesium, carbon
and oxygen
magnesium
carbonate
MgCO3
copper, carbon and
oxygen
copper
carbonate
CuCO3
sodium, hydrogen
phosphorus and
oxygen
sodium
dihydrogen
phosphate
NaH2PO4
Elements present
Name of
compound
Formula
nitrogen and
hydrogen
ammonia
NH3
potassium, hydrogen
and oxygen
potassium
hydroxide
KOH
magnesium and
oxygen
magnesium
oxide
MgO
hydrogen and
oxygen
water
H2O
nitrogen, hydrogen
and chlorine
ammonium
chloride
NH4Cl
nitrogen, hydrogen
and oxygen
ammonium
nitrate
NH4NO3
copper, sulfur and
oxygen
copper
sulfate
CuSO4
6
7
a
b
c
d
e
a
b
8
a
physical change
chemical reaction
chemical reaction
chemical reaction
physical change
zinc + hydrochloric acid → zinc chloride +
hydrogen
carbon dioxide + water → glucose +
oxygen
i
methane + oxygen → carbon dioxide
+ water
ii reactants: C = 1 / H = 4 / O = 4
products: C = 1 / H = 4 / O = 4
The numbers of each type of atom
are the same on both sides of
the equation.
iii CH4(g) + 2O2(g) → CO2(g) + 2H2O(l)
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Chapter 5
Exercise 5.1
1
a
b
i
twice
ii double
iii less
iv
twice; double; twenty-four; third; relative
v
half
four times
Exercise 5.2
2
a
b
percentage of nitrogen (%) = (mass of nitrogen × 100) / relative formula mass
percentage of nitrogen (%) = (28 × 100) / 80 = 35%
every 100 g of ammonium nitrate contains 35 g
Exercise 5.3
3
4
Chemical term
Definition
mass number
a carbon-12 atom is given a mass of exactly 12
the standard for measuring
relative atomic mass
the number of protons and neutrons in the nucleus of an
atom; also called the nucleon number
relative atomic mass, Ar
the sum of all the relative atomic masses for the atoms in
a molecule; use only for covalent substances
isotopes
atoms of the same element with different nucleon
numbers; they have different numbers of neutrons
relative molecular
(or formula) mass, Mr
the average mass of an atom of an element, using a scale
where an atom of carbon-12 has a mass of exactly 12
a
b
b
isotopes; isotopes
atoms; atoms; isotopes
Exercise 5.4
5
a
b
c
d
6
7
One mole of a substance has a mass equal
to the molecular (or formula) mass of the
substance in grams.
Avogadro’s constant is the number
of atoms, molecules or characteristic
particles in one mole of a substance.
One mole of a substance contains 6.02
× 1023 (Avogadro’s constant) atoms,
molecules or other characteristic particles.
Avogadro’s constant = 6.02 × 1023 atoms,
molecules or other characteristic particles.
one; two; two
2 × 24 = 48 g + 32 g → 80 g
0.80 g of magnesium oxide
Carry out the exercise to familiarise yourself
with the mathematical expressions.
Exercise 5.5
8
7
a
solute; solvent; soluble; insoluble;
dilute; concentrated
c
Use a balance to measure out 1.0 g of
sodium chloride and then add the solid to
the water in the beaker. ✓
Measure 50 cm3 of distilled water in a
measuring cylinder and pour it into a
beaker. ✓
Carry on adding small portions of salt to
the solution until no more dissolves. ✓
Stir the mixture with a glass rod until all
the salt has dissolved. ✓
1 Take a 100 cm3 measuring cylinder.
Fill it approximately half full with
distilled water.
2 Use a balance to carefully measure out
1.0 g of copper sulfate.
3 Use a small filter funnel to pour the
solid into the measuring cylinder.
4 Wash out any remaining solid on the
filter funnel with a little distilled water.
5 Shake the cylinder gently until all the
solid has dissolved.
6 With gentle shaking, add more distilled
water to the solution, until the level of
the solution is exactly at the 100 cm3
mark on the neck of the cylinder.
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Chapter 6
Exercise 6.1
1
a
b
i
to split
ii to electrolyse
iii to discharge
iv to decompose
to split and to decompose
c
d
Exercise 6.2
2
a
is carried out; are connected; becomes;
reach; are discharged; splits; move; is
switched on; move; occurs; lose; are oxidised
i
move; are discharged; gain electrons;
are gained; is formed; 2e–
ii move; are discharged; lose; are lost;
is formed; Br2
battery
electrons repelled into
wire from negative
–
terminal
+
electrons attracted
to positive terminal
A
ammeter
solid
b
i
ii
iii
iv
v
8
light
bulb
Solid
Appearance of solid
Test result
Conductor or insulator
A
shiny, light grey rod
bulb lit up and current
recorded
conductor
B
hard brown rod
bulb did not light up and
no current recorded
insulator
C
black rod
bulb lit up and current
recorded
conductor
D
yellow block
bulb did not light up and
no current recorded
insulator
E
red–brown strip
bulb lit up and current
recorded
conductor
C
A and E
B
D
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Chapter 6 continued
Exercise 6.3
3
a
b
1–C; 2–A; 3–D; 4–B
i
As
ii Therefore
iii As
iv Therefore
v As
Exercise 6.4
4
a
i
ii
iii
iv
b
9
elements
compound; produces
oxygen; water
2H2 + O2 → 2H2O
opposite
Across
1 elements
3 negative
6 water
9 two
10 redox
12 graphite
15 electroplating
18 oxygen
Down
2 electrolytic cell
4 battery
5 decompose
7 electrolyte
8 ions
11 hydrogen
13 oxidation
14 copper
16 lead
17 anode
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Chapter 7
5
Exercise 7.1
1
a
b
i
different; to
ii between
iii different; from
iv same; as
The major feature of a chemical change,
or reaction, is that new substances are
made during the reaction.
Many reactions, but not all, are difficult
to reverse.
During a chemical reaction, energy can be
given out or taken in. Most reactions give
out energy.
6
a
i
ii
iii
iv
b
enthalpy change of reaction =
2736 – 3462 = -726 kJ / mol
break; covalent; releases; released; –;
exothermic; formed; used; broken
i
Key points:
• the products have higher energy
than the reactants, so the reaction
is endothermic
• ∆H arrow is pointing upwards, so
value is positive
• activation energy (Ea) is needed
for the reaction to take place
ii The product’s energy level would be
below that of the reactants and the
∆H arrow would point downwards.
i
Bond energy is the energy needed to
break one mole of the bonds.
ii The heat of combustion is the energy
given out when one mole of the
substance is completely burned.
iii Activation energy is the minimum
energy needed for the reaction to
take place.
a
Exercise 7.2
2
3
a
b
c
d
e
a
b
Given that; chemical reaction
Since; physical change
For this reason; chemical reaction
Given that; physical change
For this reason; chemical reaction
exothermic
endothermic
b
Exercise 7.3
a
b
vertical; products; progress; horizontal
i
exothermic reaction
Energy / kJ
reactants
products
heat
given
out
progress of reaction
products
heat
given
out
action
Energy / kJ
ii
Energy / kJ
4
M = making (bonds)
B = breaking (bonds)
EXO = exothermic
ENDO = endothermic
products
reactants
heat
taken
in
progress of reaction
endothermic reaction
products
heat
taken
in
reactants
progress of reaction
10
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Chapter 8
Exercise 8.1
Exercise 8.2
1
2
a
b
c
d
e
11
Hydrogen and oxygen take part in an
explosive reaction that can be used to
power rockets.
Photosynthesis is a reaction that takes
place in the leaves of green plants.
Copper carbonate is green coloured
and is stable at room temperature but
decomposes quickly when heated with a
Bunsen burner, producing a black powder.
OR
Copper carbonate is coloured green
and is stable at room temperature but
decomposes quickly when heated with a
Bunsen burner, producing a black powder.
The metal zinc reacts with copper sulfate
solution and the blue colour of the
solution fades.
OR
The metal zinc reacts with blue copper
sulfate solution and the colour of the
solution fades.
The vigorous reaction between calcium
carbonate and dilute hydrochloric acid
produces a large volume of gas.
a
b
K
H
T
I
M
E
I
W
Z
K
V
S
I
R
R
C
T
N
E
X
P
L
O
S
I
V
E
E
S
R
O
E
M
J
P
L
X
R
Y
C
H
A
U
I
E
N
M
T
N
E
J
U
H
A
V
C
R
N
D
A
C
P
J
E
W
B
P
T
A
T
F
C
K
E
C
E
E
J
E
W
C
A
R
I
A
R
N
B
C
T
N
R
J
S
M
L
I
O
N
C
E
S
P
F
R
A
T
A
B
I
Y
A
E
A
O
R
A
U
E
N
R
T
O
S
B
R
A
S
E
O
S
Q
E
A
T
A
U
T
L
A
R
E
S
D
T
E
W
Y
S
Y
T
R
E
T
E
S
L
U
H
B
I
T
Z
E
J
I
E
E
A
I
O
C
T
T
Y
M
F
Y
S
S
O
F
A
S
W
T
P
R
E
S
S
U
R
E
F
N
concentration; surface area; pressure;
temperature; catalyst
Exercise 8.3
3
4
a
b
c
a
b
c
d
concentrated; more concentrated; least
concentrated
high; higher; highest
largest; smallest; lowest; greater; greatest
fastest; slowest
greater; increases
smaller; closer; more; increases
faster; more; higher
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Chapter 8 continued
Exercise 8.4
5
a
b
horizontal axis ​origin ​curve ​slope ​change ​points ​plateau ​gradient ​dependent ​variable ​
tangent ​point ​flattens out ​trend ​best-fit line ​straight line ​outlier ​measure ​independent
variable ​vertical axis
Terms (word or
combination of words
Definition
horizontal axis
The x-axis of the graph; the axis along which the independent variable (the
variable you change) is plotted
vertical axis
The y-axis of the graph; the axis along which the dependent variable (the
variable you measure) is plotted
outlier
An anomalous point that does not fit close to the curve or straight line of
the graph; the line of the graph should not include this point
origin
The point 0,0 of the graph
The slope or gradient
of the graph
The rate of change shown by the graph; the steepness of the curve shows
how quickly the reaction is taking place
tangent
A straight line drawn at a point on the curve of the graph, used to work out
the rate of reaction at that time
best-fit line
The line drawn that passes through or as close to as many points as
possible; this can show the overall trend in the results
plateau
The part of the graph where the curve flattens out, showing no further
reaction
i
ii
iii
At B, the gradient has decreased. This
shows that less product is formed in a
given time. The reaction is slower here.
At C, the gradient is very small. This
shows that only a small amount of
product is being formed. The reaction is
slowing down.
At D, the graph has flattened. This shows
that no more product is being formed.
The reaction has stopped.
Exercise 8.5
6
a
b
effects
affects
c
d
effect
affects; effect
7
a
b
12
effect
iv / iii / i / ii / v
A catalyst is a substance that speeds up the
rate of a chemical reaction without being
used up during the reaction. The catalyst
is chemically unchanged at the end of
the reaction.
biological; catalysts; affect; faster;
milder; without
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Chapter 9
Exercise 9.1
1
a
b
c
3
anhydrous
making something
absorb water (n)
aqueous
dried (water has been
lost or removed) (adj)
dehydrated
making something
lose water (n)
hydration
containing no water
(adj)
dehydration
made of or containing
water (adj)
decomposition; split up; simpler;
decomposes; reverse; dehydration;
dehydrated; anhydrous; dehydration
dehydrated; crystallised; carried out; added;
reversed; combined; used
Exercise 9.2
2
a
b
i
ii
13
Position on
diagram
Label
reaction vessel
H
condenser
F
iron catalyst
B
liquid ammonia
D
recycled nitrogen and
hydrogen gases
C
temperature of about 450 °C
G
mixture of nitrogen and
hydrogen gases enters
A
pressure of 20 000 kPa
E
1
2
3
4
5
6
7
A
D
F
G
E
B
C
Exercise 9.3
4
5
a
b
c
d
e
f
a
b
might
should
will; will
will
will
will
In general, a decrease in pressure will
move the equilibrium position to the
side of the reaction that has the higher
number of moles. This side will occupy a
higher volume.
In general, a decrease in temperature
will move an equilibrium position in the
direction of the exothermic reaction.
There will be more ammonia in the
equilibrium mixture.
Snitrogen
Tiron catalyst
Ucompressed
V
The hydrogen and nitrogen are
mixed in a ratio of 3:1.
Wcondensed
Xrecycled
Yammonia
Zhydrogen
1
2
3
4
5
6
7
8
S
V
U
T
Z
W
X
Y
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Chapter 10
Exercise 10.1
Exercise 10.4
1
6
a
b
oxidised; reduced
An oxidising agent is a substance that
will give (add) oxygen to another element
or compound.
a
2
reduction
iron oxide + carbon monoxide → iron + carbon dioxide
b
oxidation
Exercise 10.2
3
a
b
c
d
In the blast furnace, iron(III) oxide
(usually in the form of hematite) is
reduced to iron metal by the reducing
agent (carbon monoxide). However,
in this process the carbon monoxide is
oxidised to carbon dioxide. This is a redox
reaction as one substance loses oxygen
while another gains it.
In the extraction of aluminium the
aluminium ions (Al3+) present in the
electrolyte gain electrons to form
neutral aluminium atoms. This is a
reduction reaction.
Oxidation is the loss of electrons.
Reduction is the gain of electrons.
An oxidising agent is a substance which
will remove electrons from an atom,
molecule or ion.
A reducing agent is a substance that will
give electrons to an atom, molecule or ion.
Exercise 10.3
4
a
b
This is a reduction as electrons are gained
as chlorine atoms become chloride ions.
This is a reduction as electrons are lost as
iodide ions become iodine atoms.
c
reduction
chlorine + potassium iodide → potassium chloride + iodine
oxidation
5
14
Compound
Oxidation
number of
metal present
Formula of
metal ion
present
copper(II) sulfate
+2
Cu2+
iron(III) oxide
+3
Fe3+
cobalt(II) chloride
+2
Co2+
copper(I) oxide
+1
Cu+
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Chapter 11
Exercise 11.1
1
2
3
a
An acid is a substance that gives a
solution with a pH less than 7 when
dissolved in water.
b An acid is a solution that reacts with an
alkali to give a salt and water only.
c An acid dissolves in water to give a
solution that contains an excess of
hydrogen ions.
• All bases neutralise acids.
• Bases include metal oxides and
hydroxides.
• Alkalis are soluble bases.
• Not all bases are alkalis.
Acids: ions; lower; red; neutralised; only
Bases: hydroxides; insoluble
Alkalis: dissolve; excess; ions; higher; red
Exercise 11.2
4
less acidic; the least acidic
B<C<A
the least
more alkaline; the least
X>Y=Z
more concentrated
Exercise 11.3
15
5
strong; covalent; completely; chloride; weak;
some; less; lower; higher; more
6
Statement
True / False
A sulfuric acid solution is less
corrosive than a solution of
ethanoic acid.
False
A hydrochloric acid solution will
conduct electricity better than
an ethanoic acid solution.
True
An ethanoic acid solution will
produce carbon dioxide gas at
a faster rate than a hydrochloric
acid solution when reacted with
calcium carbonate.
False
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Chapter 12
Exercise 12.1
Exercise 12.3
1
3
a
b
c
i
ii
iii
i
ii
iii
iv
v
i
ii
iii
on
of
on
consist of
results in
depends on
dependent on
depends on
The acidity of a solution depends on
the concentration of hydrogen ions
present.
Adding an alkali to an acid results
in the formation of a salt and
water only.
Salts are ionic compounds consisting
of a positive metal ion and a negative
non-metal ion.
a
b
4
a
b
c
i
0.1 mol / dm3 = nought (or zero) point
one moles per decimetre cubed (or
cubic decimetre)
ii 0.5 mol / dm3 = nought (or zero) point
five moles per decimetre cubed (or
cubic decimetre)
iii 20 g / dm3 = twenty grams per
decimetre cubed (or cubic decimetre)
iv 0.2 mol per 200 cm3 = 1 mol / dm3 =
one mole per decimetre cubed (or
cubic decimetre)
i
the amount of substance
ii the volume of the solution
iii Student exercise
burette; acid; volume; pipette
indicator; colour; end point
evaporated; filtered
Exercise 12.2
2
a
b
16
i
A measuring cylinder was used to add
25 cm3 of dilute hydrochloric acid to a
beaker.
ii Then some solid magnesium
carbonate was added to the acid in
the beaker.
iii The reaction mixture was stirred with
a glass rod.
iv More solid was carefully added to
the acid in small amounts so that
the mixture did not froth out of
the beaker.
v Further solid was added until there
was no more fizzing and some solid
was left in the bottom of the beaker.
The mixture was stirred and filtered to
remove the excess solid. The filtrate was
then put in an evaporating basin and
heated. It was heated until crystals formed
at the edges of the solution. The Bunsen
burner was removed and the solution left
to cool slowly. After a time the crystals
were filtered off and dried between pieces
of filter paper.
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CAMBRIDGE IGCSE™ CHEMISTRY: ENGLISH LANGUAGE SKILLS WORKBOOK
Chapter 13
Exercise 13.1
1
a
b
c
d
e
f
g
h
hydrogen
halogen
non-metal
vertical; groups
noble gases
horizontal; period
transition
elements
T
O
I
O
L
A
N
N
E
E
H
E
O
I
T
L
A
T
G
R
O
U
P
I
S
N
A
R
T
A
T
N
O
Z
I
R
O
H
G
N
S
O
C
O
I
G
H
N
O
L
S
N
E
R
H
A
B
A
O
E
A
Z
E
D
N
N
R
R
L
E
L
L
R
O
A
O
S
O
O
H
O
L
O
O
E
K
D
I
T
T
T
I
N
H
E
L
G
O
I
A
Y
T
E
S
N
R
M
S
N
E
E
N
I
L
H
R
H
E
S
E
E
E
R
L
N
T
L
I
L
T
O
S
N
P
T
L
O
E
E
A
I
N
E
R
R
A
O
M
A
P
I
U
R
T
L
E
N
E
O
G
E
E
L
N
P
I
S
I
R
V
E
R
T
I
C
A
L
E
D
N
L
M
E
P
R
L
N
G
S
T
N
E
M
E
L
E
Exercise 13.2
2
a
Statement
True
The first attempts to make a table of the elements placed them in order of increasing
atomic mass.
✓
The sequence of the elements is the same, whether it is based on their proton number or
their atomic mass.
The sequence of the elements is split into rows, based on the electron shells being filled in
their atoms.
✓
✓
The splitting of the sequence of elements gives us a table consisting of horizontal groups
and vertical periods.
b
17
✓
Usually, as you move down a group in the Periodic Table, the number of electrons in the
outer shell of the atoms is the same.
✓
The first row of the table only has two elements in it, because the first electron shell can
only hold two electrons.
✓
All the elements in Group VII of the table have eight electrons in their outer shell.
i
ii
iii
iv
v
vi
vii
False
✓
continuous
two-dimensional
electronic configuration
group
period
outer shell
energy level
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Chapter 13 continued
3
a
b
1 the melting A
point
5 The chart
2 the melting C
points
6 the melting B
points
3 the
elements
C
7 The
melting
points
4 the proton
number
C
8 the highest C
values
A
C
the; a; the; the; the; a; the
Exercise 13.3
4
a
b
c
d
e
5
18
Sodium is a highly reactive metal in
Group I. It reacts vigorously with
cold water.
Transition elements form a block in the
middle of the Periodic Table. They are
especially useful, strong metals.
Fluorine is the most reactive of the
elements in Group VII. It can react
explosively, and it will displace other
halogens from compounds.
Atoms of the elements get smaller as
we move across a period in the table.
As they get smaller the elements
concerned become less metallic.
The elements of Group I are very reactive,
and their reactivity increases as we go
down the group.
Pronoun What the reference is
number referring to
1
metals
2
metals
3
alkali metals
4
non-metals
5
transition from metals to
non-metals
6
a metal or non-metal
7
copper
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CAMBRIDGE IGCSE™ CHEMISTRY: ENGLISH LANGUAGE SKILLS WORKBOOK
Chapter 14
Exercise 14.1
1
a
4
A
B
C
E
L
E
R
E
A
C
T
M
A
L
L
E
A
B
L
E
C
T
R
O
D
E
S
R
U
B
I
D
C
O
N
D
L
Y
D
E
I
U
M
U
C
T
S
I
E
L
E
C
T
R
O
G
D
U
C
T
I
L
E
M
O
N
O
X
I
D
E
S
O
N
O
R
O
U
I
c
V
F
H
b
I
3
19
E
b
S
S
1
Reduction is the removal of oxygen
from a compound.
2 Reduction is the gain of electrons by
an atom, ion or molecule.
regular; lattice; lose; stronger; between;
positive; conduct; heat; metallic; ductile
This gave a colourless solution.
The solution was acidified with dilute
nitric acid and then barium nitrate
solution added. A white precipitate
was formed, showing that the salt was
a sulfate.
The white zinc salt was dissolved in
distilled water to give a colourless
solution. Dilute sodium hydroxide
solution was added and a white
precipitate was formed. This white
precipitate redissolved on addition of an
excess of sodium hydroxide solution.
This is the positive test for zinc ions.
Exercise 14.3
5
Exercise 14.2
2
a
a
Gap
Gap
1
brass
8
lattice
1
2
3
4
5
2
copper
9
metallic
C
A
E
D
B
3
carbon
10
electricity
4
transition
11
ductile
5
stainless
12
positive
6
chromium
13
delocalised
7
molten
14
slide
Key word
Meaning
dilute
hydrochloric
acid
a solution of a substance in a
large amount of water (noun)
fizzing
bubbles of gas forming (noun /
-ing form)
dissolves
the solid disappears forming a
solution (verb)
precipitate
a solid suddenly formed by
mixing two solutions or passing
a gas into a solution (noun)
clear
transparent and can be seen
through (adjective)
colourless
has no colour (adjective)
milky
cloudy white in colour
(adjective)
b
i
ii
iii
iv
Mild steel is used for making car
bodies because it is easy to shape
without breaking.
Solder is used for joining metals
together because it has a low
melting point.
Stainless steel is used for making
surgical instruments and cutlery
because it is resistant to rusting.
Brass is used for making decorative
objects because it is hard and
gold coloured.
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CAMBRIDGE IGCSE™ CHEMISTRY: ENGLISH LANGUAGE SKILLS WORKBOOK
Chapter 15
Exercise 15.1
1
2
Property
Alkali metals
Transition
metals
hardness
soft
hard
melting
point
low
high
density
low density
high density
colour of
solid salts
white
often coloured
reactivity
highly reactive
moderately
reactive
a
Element
Reaction with water
Reaction with air
lithium
reacts steadily
tarnishes slowly to
give a layer of oxide
2Li + 2H2O → 2LiOH + H2
sodium
reacts strongly
2Na + 2H2O → 2NaOH + H2
potassium
i
ii
iii
iv
brilliantly
explosively
slowly
strongly
6
Exercise 15.2
3
a
b
i
further; greater; lower; more/less
reactive
ii more reactive; greater; further;
lower; less
Correct answer: iii
Exercise 15.3
4
5
20
a
b
c
d
a
b
c
is placed
is held
is bubbled
is passed
a–ii, b–iv, c–i, d–iii
more; will; less
will
should
increasing reactivity
tarnishes very
quickly to give a
layer of oxide
reacts violently
2K + 2H2O → 2KOH + H2
b
tarnishes quickly to
give a layer of oxide
One possible set of sentences:
Hypothesis
If one metal is more reactive than another,
it will displace the less reactive one from
solution. If we test different combinations of
metals and salt solutions we should see which
reactions take place.
Predictions
We/I think that magnesium should displace
both zinc and copper from its salts. I/
We expect to see zinc displace copper
from solution but that it will not displace
magnesium. I/We think that copper will not
displace either zinc or magnesium.
Exercise 15.4
7
a
i
ii
When magnesium is placed in
copper(II) sulfate solution the
blue colour of the solution fades,
suggesting that magnesium is more
reactive than copper.
There is no observed reaction when
copper is placed in magnesium sulfate
solution, which means that copper is
less reactive than magnesium.
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Chapter 15 continued
iii
b
21
i
ii
There is a reaction when magnesium
is placed in iron(II) sulfate solution.
This means that magnesium is more
reactive than iron.
copper < iron < magnesium
Iron reacted with copper sulfate
solution, but it did not displace
magnesium from solution. This means
that iron is more reactive than copper,
but is less reactive than magnesium.
Copper did not react with either iron
sulfate or magnesium sulfate.
This suggests that it is the least
reactive of these three metals / it is less
reactive than iron or magnesium.
Magnesium reacts with both copper
sulfate and iron sulfate solutions.
This means that it is more reactive
than iron or copper.
Therefore, we can conclude that
magnesium is the most reactive of
these metals, and copper is the least
reactive of the three.
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Chapter 16
c
Exercise 16.1
1
a
b
Key word
1
2
3
4
5
6
7
8
Definition
C
F
E
G
D
A
H
B
T
E
i
ii
iii
limestone, iron ore, coke
molten iron, slag, waste gas
tapped off (a process, not a
chemical substance)
Stainless steel is an alloy of iron that is
resistant to rusting. This metal contains
iron that has been mixed with another
transition metal that does not corrode
easily in order to improve the resistance
to rusting.
Exercise 16.2
2
a
A
B
C
C
B
A
U
X
I
R
Y
O
L
I
T
E
R
E
D
D
C
T
I
O
N
O
L
T
E
N
V
E
P
H
I
T
E
E
N
E
G
A
T
I
F
O
X
Y
G
E
N
G
R
A
G
b
U
M
Al2O3
Exercise 16.3
3
4
5
22
light; good; alloys; metals; low; corrosion;
recycling; expensive; large
a air (oxygen) and water
b i
paint, plastic or oil
ii Iron objects are covered with plastic,
or by painting, to produce a barrier
so that air and water cannot get to the
surface of the iron.
a Blocks of a metal that is more reactive
than iron are attached to the iron or steel
object in order to prevent rusting. The
blocks of metal react with the air and
water in preference to the iron object.
b Coating an object with a complete layer
of zinc (galvanising) provides a total
covering for the object that acts as a
barrier preventing water and air from
coming into contact with the iron.
If the zinc layer is broken by scratching or
wear, the zinc still protects by sacrificial
protection as it is more reactive than iron.
The zinc corrodes rather than the iron.
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Chapter 17
Exercise 17.1
1
a
4
pie chart
a
b
nitrogen 78%
oxygen 21%
argon 0.90%
carbon dioxide
0.04%
b
2
a
i
ii
iii
iv
v
vi
vii
i
ii
iii
iv
v
b
c
A
B
C
i
ii
nitrogen
oxygen
xenon
helium
neon
oxygen
argon
✗
An indicator that turns yellow in
alkaline solution is methyl orange.
✓
✗
In clean dry air, carbon dioxide is the
only greenhouse gas.
✓
✗
The only gaseous compound in clean
dry air is carbon dioxide.
‘The noble gases in the air’ = ii
‘Methyl orange as an indicator’ = i
‘Carbon dioxide’ = iii
The discovery of the noble gases by
William Ramsay was remarkable as
these gases are very unreactive.
Carbon dioxide and methane are the
main greenhouse gases present in
the air.
Exercise 17.2
3
23
other noble
gases 0.06%
global warming
ozone layer
sulfur dioxide
photochemical smog
carbon dioxide
climate change
i
photosynthesis
ii combustion
Possible answers include:
i
The process in the first picture is
called photosynthesis. It is a reaction
taking place in the green leaves of
plants in which energy from the Sun
is used to convert carbon dioxide and
water into glucose.
ii The process in the second picture
is called combustion. It is a type of
reaction in which wood and fossil
fuels are burnt to produce energy.
Exercise 17.3
5
a
b
c
d
6
a
b
c
7
a
b
c
8
ozone and chlorine
Harmful organisms such as bacteria
are killed. Harmful organisms could
spread disease.
screens and sand filters
Attach some chemicals to themselves,
removing them from the water.
break down
pesticide
absorb
d
e
precipitator
reservoir
2, 1, 4, 3
A–4; B–2; C–1; D–3
i
Three-quarters of our world is
covered in water.
ii only 2.5% of water on Earth is
fresh water
iii competition for this water is growing
iv The increase in human population
means that competition for this water
is growing and underground sources
are being used up.
d The importance of water ✓
because the key word at the end of the
first sentence of the introduction is ‘water’
Possible answer:
An important step in cleaning water for
domestic use is filtration through sand/carbon.
Using sand filters out some solid particles
that would make the water unpleasant to
drink while the carbon removes some harmful
chemicals. Together this filtration is a key step
in producing clean water for domestic use.
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Chapter 18
Exercise 18.1
1
a
b
c
2
i
ethane
ii propane
iii hexane
iv octane
i
CH4
ii C3H8
iii C4H10
iv C5H12
CnH2n+2
Hydrocarbons are ...
... is methane, CH4.
The simplest
hydrocarbon ...
... butane.
The major source of
hydrocarbons ...
... because they
only contain
carbon–carbon
single bonds.
Alkanes are
saturated
hydrocarbons ...
... compounds that
contain carbon and
hydrogen only.
The fourth member
of the alkanes is ...
... is the fossil fuel
petroleum.
Exercise 18.2
3
a
b
Compound
Prefix
hexane
hex-
6
-ane
alkanes
butene
but-
4
-ene
alkenes
ethanol
eth-
2
-ol
alcohols
pentanol
pent-
5
-ol
alcohols
ethanoic acid
eth-
2
-oic acid
carboxylic acids
i
ii
iii
methanol CH3OH
ethene C2H4
ethanoic acid CH3COOH
Exercise 18.3
4
a
b
24
i
ii
iii
i
ii
iii
iv
A–2
C–1
B–3
In addition; also
as well as
In addition; also
Furthermore; and
Number of carbon Suffix
atoms in chain
c
i
ii
iii
Homologous series
Unlike alkanes containing carbon
and hydrogen atoms, alcohol and
carboxylic acid molecules also contain
oxygen atoms.
Pentene molecules contain a carbon–
carbon double bond as well as
carbon–carbon single bonds.
Carbon can exist in the form of
graphite. In addition, it can exist
in other structural forms such
as diamond.
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CAMBRIDGE IGCSE™ CHEMISTRY: ENGLISH LANGUAGE SKILLS WORKBOOK
Chapter 19
Exercise 19.1
1
A
5
C A R B O N
B
S A T U R A T E D
C
D E C A N E
D
A L
E
B
F
G
H
2
3
K A N E
I
S
T U M E N
C O V A L
E N T
E T H A N O L
A L
K E N E
S
a
Because both the skeleton and a
hydrocarbon molecule have a chain of
repeating units to which other structures
are attached.
i
Each
ii Each
iii Both
iv Each
v Both
b i
Both
ii Each
iii both
iv whereas
v Whereas
c i
Alkanes are saturated hydrocarbons
whereas alkenes are unsaturated.
ii Both ethane and propane are alkanes
even though they contain different
numbers of carbon atoms.
d a functional group / e.g. –COOH
ethene; water; colourless; unsaturated;
reaction; orange
Exercise 19.2
4
25
a
b
c
d
e
butane
three
C4H10 / CH3CH(CH3)CH3
compounds; same; structures; isomerism
but-2-ene
A
B
C
D
E
F
G
H
O
M
O
L
O
G
O
U
S
F
R
P
R
O
E
A
V
C
T
F
I
U
S
L
F
N
E
T
H
E
N
E
N
N
T
V
A
O
G
P
H
W
E
H
G
C
R
P
K
M
L
O
I
A
J
S
L
T
U
E
J
E
A
L
K
A
N
E
E
I
C
T
O
R
H
Y
G
P
R
E
Z
O
T
H
I
S
O
M
E
R
I
S
M
N
U
A
H
S
D
E
R
L
X
N
D
A
R
N
R
Y
C
R
N
O
E
O
I
L
A
O
B
S
A
T
U
R
A
T
E
D
L
L
X
V
L
C
O
V
A
L
E
N
T
homologous
covalent
methane
alkane
single
saturated
ethene
H
I
J
K
L
M
ethanol
functional
structural
isomerism
polymer
monomer
Exercise 19.3
6
7
a
b
a
b
butanol; C4H9OH
propanoic acid; C2H5COOH
i
Despite
ii Although
iii However
iv Whereas
i
An addition reaction produces just
one product, whereas a substitution
reaction will produce two products.
The reaction of steam and ethene
gives just one product and so is an
addition reaction.
ii Non-renewable resources have a finite
lifetime and will eventually be used
up. However, renewable resources can
be replaced by newly grown materials.
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CAMBRIDGE IGCSE™ CHEMISTRY: ENGLISH LANGUAGE SKILLS WORKBOOK
Chapter 20
Exercise 20.1
Exercise 20.2
1
3
2
a
b
c
a
b
c
d
e
26
A refinery gas
B petrol (gasoline)
C paraffin (kerosene)
D diesel oil
E lubricating oil
A
E
decane → octane + ethene
Monomer
Polymer
ethene
CH2=CH2
poly(ethene)
propene
CH2=CHCH3
poly(propene)
styrene
CH2=CHC6H5
poly(styrene)
chloroethene CH2=CHCl
4
poly(chloroethene)
Addition; polymers; broken; Poly(ethene);
Fatty acids; monomers; natural; artificial;
biodegradable
Decane
(a liquid)
Ethene
(a gas)
Exercise 20.3
Hydrocarbon
series
alkane
alkene
Saturated or
unsaturated?
saturated
unsaturated
Reacts with
bromine
water? Yes/No
no
yes
Boiling point
above/
below room
temperature
above
below
Possible answers:
5 a In conclusion, while valuable minerals
are obtainable by mining the ocean
floor, the potential ecological damage
to the seabed must also be taken into
serious consideration.
b Therefore, in order to prevent the further
loss of environmentally important
rainforest habitats, we must impose
greater control on the clearing of forest
areas for townships and ranching.
6 In conclusion, there are issues to be resolved
in developing hydrogen as a fuel. These
include finding methods for safe storage and
the development of an extensive infrastructure
for distribution. However, with its high energy
output, its use as an environmentally clean
fuel needs to be exploited.
7 Here are some ideas for the different sections
of your answer:
Introduction
Statements as to how significant plastics have
become and the essential problems.
Advantages – the usefulness of polymers
(one or two main examples)
Include ideas about how the introduction
of plastics has positively affected our lives –
lightweight materials / durability and freedom
from corrosion / ease of shaping, moulding
and shaping objects / mass production
Disadvantages of the use of polymers
(e.g. waste disposal, plastic in the oceans)
Problems of waste disposal / non-biodegradable
products that are consuming resources / impact
of waste on land and in the oceans
Conclusion
Give your own summary and opinion.
long-; shorter; alkane; short
i
Consequently
ii Therefore
iii Because
iv so
v because
vi Consequently
i
The alkali metals all react with
oxygen and water vapour in the air.
Consequently, the alkali metals must
be stored under oil.
ii Because litmus changes colour in acid
and alkaline solutions, it can be used
as an acid–base indicator.
iii Alkanes and alkenes react differently
with bromine water, so bromine
water can be used as a test to
distinguish them.
iv The electronic configurations of noble
gas atoms are very stable. Therefore,
the noble gases exist as single atoms
and are very unreactive.
Cambridge IGCSE™ Chemistry – Harwood & Chadwick © Cambridge University Press 2022
CAMBRIDGE IGCSE™ CHEMISTRY: ENGLISH LANGUAGE SKILLS WORKBOOK
Chapter 21
Exercise 21.1
1
a
b
c
Verb
-ing form
Noun – name of
process
Noun – product of
process
to condense
condensing
condensation
the condensate
to separate
separating
separation
to distil
distilling
distillation
the distillate
to filter
filtering
filtration
the filtrate
to precipitate
precipitating
precipitation
the precipitate
to neutralise
neutralising
neutralisation
to calculate
calculating
calculation
to titrate
titrating
titration
to oxidise
oxidising
oxidation
to reduce
reducing
reduction
to purify
purifying
purification
b
precipitation; precipitate
filtration; filtered; filtrate
separating; purifying; Filtering;
precipitating; titrating; distilling
3
27
i
ii
Exercise 21.2
2
the titre
The following is one suggested description.
You should check you have the same ideas
even though your sentences will be different.
The seawater is heated in the flask. The boiling
point of water is much lower than that of salt.
When the temperature reaches its boiling
point, the water boils. The boiling point of
salt is much higher so it remains in the flask.
The water vapour passes from the flask into
the condenser. Cold water flows through the
outer jacket of the condenser. The water
vapour cools down and condenses back to a
liquid in the condenser. The pure water flows
from the condenser into the flask. Pure water
is the distillate.
a i
by
ii in (by could also be used)
iii to
iv in
v at
vi with
iii
iv
v
vi
Carl Bosch is the person with
whom Fritz Haber worked on
developing the industrial process for
making ammonia.
A volumetric pipette is the apparatus
with which to measure out an accurate
volume of solution.
In an acid–alkali titration the
end point is the point at which the
indicator just changes colour.
Group VII of the Periodic Table is the
group in which we find the halogens
such as chlorine.
The boiling point of a liquid is the
temperature at which it turns into
a gas.
Barium nitrate solution is the reagent
with which we test for a sulfate.
Exercise 21.3
4
5
a
b
time and solubility in the solvent
No, none of the spots present in the
samples are at the same distance up
the paper.
a B
b A
c B
d A
e B
All these choices give correct advice.
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CAMBRIDGE IGCSE™ CHEMISTRY: ENGLISH LANGUAGE SKILLS WORKBOOK
Chapter 21 continued
6
6 allowed solvent to rise up the paper
7followed how the solvent rose up the paper
and how the spots separated
8removed the paper from the solvent before
the front reached the top of the paper
9carefully hung the paper to dry
10analysed and measured the distances moved
by the spot
7 Method to include the following points:
• Choice of solvent – try dissolving the two
samples of saffron to get a concentrated
solution of the yellow colour.
• Dissolve and concentrate the two samples
of saffron.
• Prepare chromatography paper – with
pencil baseline.
• Carefully spot the two samples in position
on the baseline.
• Assemble beaker and shallow layer
of solvent.
• Place chromatogram in the solvent chosen
and allow solvent to rise up the paper.
• Stop the separation before solvent
overruns the top of the paper.
• Remove paper and dry carefully / analyse
spots to see if the two samples move the
same distance or not.
28
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CAMBRIDGE IGCSE™ CHEMISTRY: ENGLISH LANGUAGE SKILLS WORKBOOK
Chapter 22
Exercise 22.1
1
a
i
ii
iii
iv
The pH can be measured using
universal indicator paper – this would
give an approximate value. A more
accurate value can be found using an
electronic pH meter.
by using a flame test / a nichrome wire
is dipped in the water sample and
then held on a strong Bunsen burner
flame / a yellow colour to the flame
indicates the presence of sodium ions.
the flame test gives a quick and clear
indication of the presence of certain
metal ions / restricted to those metals
that give a distinctive colour to
the flame
precipitation tests are available for
various metals that have insoluble
and coloured hydroxides / but also for
zinc and aluminium that give white
hydroxide precipitates / these tests are
more involved than the flame test
one litre of water must be carefully
evaporated to dryness / use an
evaporating basin that has first been
weighed / evaporate the water in
batches in this basin / be careful not
to let any water spray out / when all
the water has been evaporated, weigh
the evaporating basin again to find
the mass of the dry residue
Exercise 22.2
2
a
b
C/D/B/A
First of all, heat up the nichrome wire in a
hot Bunsen flame.
Then dip the wire into concentrated
hydrochloric acid.
Next, dip the wire into a pile of crystals
of the sample being tested.
Finally, hold the wire in the hot Bunsen
flame and note the colour produced by
the sample.
Exercise 22.3
3
a
i
ii
iii
iv
v
vi
4
4
the solutions being used
the halogen solution used
the observation seen
no change
Test solution
KCl solution
chlorine water
29
bromine water
No change
iodine water
No change
KBr solution
KI solution
Solution turns brown
Solution turns brown
Solution turns brown
No change
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CAMBRIDGE IGCSE™ CHEMISTRY: ENGLISH LANGUAGE SKILLS WORKBOOK
Chapter 22 continued
b
c
iodine → bromine → chlorine
i
Concluding paragraph 1:
sentences D / F / B
Concluding paragraph 2:
sentences E / A / C
ii In conclusion, study of the Periodic
Table shows that the reactivity of
the elements in a group in the table
does vary as we go down the group.
However, it is clear from looking at
Groups I and VII that the direction of
the trend varies depending on whether
the elements are metals or non-metals.
Therefore, it is important to keep the
distinction between metals and nonmetals in mind when describing trends
in the table.
Exercise 22.4
4
a
b
c
d
30
Step 1: First of all, dissolve a sample of
magnalium in dilute hydrochloric acid to
obtain a colourless solution.
Step 2: Split the solution into portions
and add sodium hydroxide solution
dropwise to both samples. Observe the
precipitate formed.
Step 3: Finally, add further drops of
sodium hydroxide to the samples and
observe whether the precipitate redissolves
or not.
Al3+ and Mg2+
precipitate A: magnesium hydroxide
precipitate B: aluminium hydroxide
Take the solution and add a few drops of
dilute nitric acid. Then add silver nitrate
solution dropwise to the solution and
observe whether a precipitate is formed.
The formation of a white precipitate
shows that chloride ions (Cl-)
were present.
Cambridge IGCSE™ Chemistry – Harwood & Chadwick © Cambridge University Press 2022