IGCSE Chemistry with Complete Solutions
A sample of carbon contained 98.90% carbon-12 and 1.10% carbon-13. Calculate the
relative atomic mass of carbon - ANSWER-((12x98.90)+(13x1.10))/100 = 12.01
acid + alkali -> - ANSWER-acid + alkali -> salt + water
acid + alkali -> - ANSWER-acid + alkali -> salt + water
acid + alkali -> - ANSWER-acid + alkali -> salt + water
acid + base -> - ANSWER-acid + base -> salt + water
acid + base -> - ANSWER-acid + base -> salt + water
acid + base -> - ANSWER-acid + base -> salt + water
acid + metal -> - ANSWER-acid + metal -> salt + hydrogen
acid + metal -> - ANSWER-acid + metal -> salt + hydrogen
acid + metal -> - ANSWER-acid + metal -> salt + hydrogen
acid + metal carbonate -> - ANSWER-acid + metal carbonate -> salt + carbon dioxide +
water
acid + metal carbonate -> - ANSWER-acid + metal carbonate -> salt + carbon dioxide +
water
acid + metal carbonate -> - ANSWER-acid + metal carbonate -> salt + carbon dioxide +
water
After adding nitric acid and silver nitrate to a solution containing iodide ions, what colour
precipitate is formed? - ANSWER-A yellow precipitate (of silver iodide) is formed.
Ammonia and hydrogen chloride react together in a reversible reaction to produce a
white solid. What are the word and symbol equations? - ANSWER-ammonia + hydrogen
chloride <-> ammonium chloride NH₃ + HCl <-> NH₄Cl
An experiment investigates which of metals X and Z is more reactive. The result is X +
ZSO₄ -> X + ZSO₄. Which metal is more reactive? - ANSWER-Z
An experiment investigates which of metals X and Z is more reactive. The result is X +
ZSO₄ -> XSO₄ + Z. Which metal is more reactive? - ANSWER-X. This is a displacement
reaction.
,Are carbon dioxide and sulphur dioxide acidic or basic? - ANSWER-Acidic as carbon
and sulphur are non-metals
Are carbon dioxide and sulphur dioxide acidic or basic? - ANSWER-Acidic as carbon
and sulphur are non-metals
Are metal oxides acidic or basic? - ANSWER-Basic
Are metal oxides acidic or basic? - ANSWER-Basic
Are non-metal oxides acidic or basic? - ANSWER-Acidic
Are non-metal oxides acidic or basic? - ANSWER-Acidic
Balance the equation for the reaction: ___ HCl(aq) + ___ MnO₂(s) -> ___MnCl₂(aq) +
___H₂O(l) + ___ Cl₂(g) - ANSWER-4 HCl(aq) + MnO₂(s) -> MnCl₂(aq) + 2H₂O(l) + Cl₂(g)
Balance the equation for the reaction: ___ HCl(aq) + ___ MnO₂(s) -> ___MnCl₂(aq) +
___H₂O(l) + ___ Cl₂(g) - ANSWER-4 HCl(aq) + MnO₂(s) -> MnCl₂(aq) + 2H₂O(l) + Cl₂(g)
Balance the following equation: WO₃ + H₂ -> W + H₂O - ANSWER-WO₃ + 3H₂ -> W +
3H₂O
Balance the following equation: WO₃ + H₂ -> W + H₂O - ANSWER-WO₃ + 3H₂ -> W +
3H₂O
Buckminsterfullerene has a simple molecular structure with weak intermolecular forces
that require little energy to overcome - ANSWER-Suggest why buckminsterfullerene,
C60, has a low melting point.
Buckminsterfullerene has a simple molecular structure with weak intermolecular forces
that require little energy to overcome - ANSWER-Suggest why buckminsterfullerene,
C60, has a low melting point.
Buckminsterfullerene has a simple molecular structure with weak intermolecular forces
that require little energy to overcome - ANSWER-Suggest why buckminsterfullerene,
C60, has a low melting point.
Calculate the relative formula mass(Mr) of zinc phosphide (Zn₃P₂) - ANSWER-257
Calculate the relative formula mass(Mr) of zinc phosphide (Zn₃P₂) - ANSWER-257
Complete the equation for the reaction by inserting the state symbols: 2Li(....) +
2H₂O(....) -> 2LiOH(...) + H₂(....) - ANSWER-2Li(s) + 2H₂O(l) -> 2LiOH(aq) + H₂(g)
,Complete the equation for the reaction by inserting the state symbols: 2Li(....) +
2H₂O(....) -> 2LiOH(...) + H₂(....) - ANSWER-2Li(s) + 2H₂O(l) -> 2LiOH(aq) + H₂(g)
Define metallic bonding - ANSWER-The electrostatic attraction between a regular array
of positive ions and the sea of delocalised electrons
Define metallic bonding - ANSWER-The electrostatic attraction between a regular array
of positive ions and the sea of delocalised electrons
Define metallic bonding - ANSWER-The electrostatic attraction between a regular array
of positive ions and the sea of delocalised electrons
Define metallic bonding - ANSWER-The electrostatic attraction between a regular array
of positive ions and the sea of delocalised electrons
Describe a test to show whether water is pure - ANSWER-If the sample is pure water it
will boil at 100⁰C
Describe an experiment to show that iron rusts quicker in salt water than rain water -
ANSWER-1) Set up tubes containing iron in rain water and in salt water. 2) Set up
control tube with iron and no water. 3) record mass of nails. 4) leave tubes for same
length of time. 5) measure mass change of nail. 6) repeat experiment
Describe how nitrogen oxides and sulfur dioxide contribute to acid rain - ANSWER-
Nitrogen oxides created in hot car engines and sulfur dioxide released when fossil fuels
are burned combine with water in the atmosphere to form acidic solutions
Describe how nitrogen oxides and sulfur dioxide contribute to acid rain - ANSWER-
Nitrogen oxides created in hot car engines and sulfur dioxide released when fossil fuels
are burned combine with water in the atmosphere to form acidic solutions
Describe how pure salt can be obtained from rock salt - ANSWER-1) Grind rock salt into
a fine powder. 2) Add powder to hot water and stir to dissolve salt. 3) Filter mixture. Salt
solution passes through the filter paper leaving behind the sand. 4) Boil filtrate to
evaporate some of the water. 5) Leave saturated solution to cool so that crystals of salt
form. 6) Filter cold mixture to separate the crystals from the remaining solution.
Describe how you would carry out a flame test - ANSWER-Put solid onto a wire. Put
into a blue flame
Describe how you would test for carbonate ions, CO₃²⁻ - ANSWER-Add nitric acid and
see if carbon dioxide bubbles form
Describe how you would test for Cu²⁺ ions - ANSWER-Add sodium hydroxide and a
blue precipitate will form
, Describe how you would test for Fe²⁺ ions - ANSWER-Add sodium hydroxide and a
green precipitate will form
Describe how you would test for Fe³⁺ ions - ANSWER-Add sodium hydroxide and a
brown precipitate will form
Describe how you would test for sulfate ions - ANSWER-Add dilute HCl, followed by
BaCl₂. A white precipitate will form
Describe the arrangement and movement of the particles in a liquid - ANSWER-
Particles are close together but irregular. The particles are free to move.
Describe the arrangement, movement and energy of the particles in a gas - ANSWER-
Particles are far apart and there are no forces between them. Energy is high. The
particles move quickly and freely.
Describe the arrangement, movement and energy of the particles in a solid - ANSWER-
Particles are close together and regularly packed. Energy is low. The particles vibrate
around a fixed point.
Describe the changes in arrangement, movement and energy of particles when a liquid
cools to become a solid - ANSWER-Arrangement becomes more regular. Particles
vibrates in a fixed position. Particles lose energy
Describe the changes in arrangement, movement and energy of particles when a liquid
turns into a solid - ANSWER-The particles form a regular arrangement, they slow down
and lose kinetic energy
Describe the chemical test for water - ANSWER-Add water to anhydrous copper(II)
sulfate which will change from white to blue if water is present
Describe the conditions under which iron rusts - ANSWER-oxygen and water
Describe the formation of a covalent bond - ANSWER-The sharing of a pair of electrons
between two nuclei
Describe the formation of a covalent bond - ANSWER-The sharing of a pair of electrons
between two nuclei
Describe the formation of a covalent bond - ANSWER-The sharing of a pair of electrons
between two nuclei
Describe the formation of a covalent bond - ANSWER-The sharing of a pair of electrons
between two nuclei
A sample of carbon contained 98.90% carbon-12 and 1.10% carbon-13. Calculate the
relative atomic mass of carbon - ANSWER-((12x98.90)+(13x1.10))/100 = 12.01
acid + alkali -> - ANSWER-acid + alkali -> salt + water
acid + alkali -> - ANSWER-acid + alkali -> salt + water
acid + alkali -> - ANSWER-acid + alkali -> salt + water
acid + base -> - ANSWER-acid + base -> salt + water
acid + base -> - ANSWER-acid + base -> salt + water
acid + base -> - ANSWER-acid + base -> salt + water
acid + metal -> - ANSWER-acid + metal -> salt + hydrogen
acid + metal -> - ANSWER-acid + metal -> salt + hydrogen
acid + metal -> - ANSWER-acid + metal -> salt + hydrogen
acid + metal carbonate -> - ANSWER-acid + metal carbonate -> salt + carbon dioxide +
water
acid + metal carbonate -> - ANSWER-acid + metal carbonate -> salt + carbon dioxide +
water
acid + metal carbonate -> - ANSWER-acid + metal carbonate -> salt + carbon dioxide +
water
After adding nitric acid and silver nitrate to a solution containing iodide ions, what colour
precipitate is formed? - ANSWER-A yellow precipitate (of silver iodide) is formed.
Ammonia and hydrogen chloride react together in a reversible reaction to produce a
white solid. What are the word and symbol equations? - ANSWER-ammonia + hydrogen
chloride <-> ammonium chloride NH₃ + HCl <-> NH₄Cl
An experiment investigates which of metals X and Z is more reactive. The result is X +
ZSO₄ -> X + ZSO₄. Which metal is more reactive? - ANSWER-Z
An experiment investigates which of metals X and Z is more reactive. The result is X +
ZSO₄ -> XSO₄ + Z. Which metal is more reactive? - ANSWER-X. This is a displacement
reaction.
,Are carbon dioxide and sulphur dioxide acidic or basic? - ANSWER-Acidic as carbon
and sulphur are non-metals
Are carbon dioxide and sulphur dioxide acidic or basic? - ANSWER-Acidic as carbon
and sulphur are non-metals
Are metal oxides acidic or basic? - ANSWER-Basic
Are metal oxides acidic or basic? - ANSWER-Basic
Are non-metal oxides acidic or basic? - ANSWER-Acidic
Are non-metal oxides acidic or basic? - ANSWER-Acidic
Balance the equation for the reaction: ___ HCl(aq) + ___ MnO₂(s) -> ___MnCl₂(aq) +
___H₂O(l) + ___ Cl₂(g) - ANSWER-4 HCl(aq) + MnO₂(s) -> MnCl₂(aq) + 2H₂O(l) + Cl₂(g)
Balance the equation for the reaction: ___ HCl(aq) + ___ MnO₂(s) -> ___MnCl₂(aq) +
___H₂O(l) + ___ Cl₂(g) - ANSWER-4 HCl(aq) + MnO₂(s) -> MnCl₂(aq) + 2H₂O(l) + Cl₂(g)
Balance the following equation: WO₃ + H₂ -> W + H₂O - ANSWER-WO₃ + 3H₂ -> W +
3H₂O
Balance the following equation: WO₃ + H₂ -> W + H₂O - ANSWER-WO₃ + 3H₂ -> W +
3H₂O
Buckminsterfullerene has a simple molecular structure with weak intermolecular forces
that require little energy to overcome - ANSWER-Suggest why buckminsterfullerene,
C60, has a low melting point.
Buckminsterfullerene has a simple molecular structure with weak intermolecular forces
that require little energy to overcome - ANSWER-Suggest why buckminsterfullerene,
C60, has a low melting point.
Buckminsterfullerene has a simple molecular structure with weak intermolecular forces
that require little energy to overcome - ANSWER-Suggest why buckminsterfullerene,
C60, has a low melting point.
Calculate the relative formula mass(Mr) of zinc phosphide (Zn₃P₂) - ANSWER-257
Calculate the relative formula mass(Mr) of zinc phosphide (Zn₃P₂) - ANSWER-257
Complete the equation for the reaction by inserting the state symbols: 2Li(....) +
2H₂O(....) -> 2LiOH(...) + H₂(....) - ANSWER-2Li(s) + 2H₂O(l) -> 2LiOH(aq) + H₂(g)
,Complete the equation for the reaction by inserting the state symbols: 2Li(....) +
2H₂O(....) -> 2LiOH(...) + H₂(....) - ANSWER-2Li(s) + 2H₂O(l) -> 2LiOH(aq) + H₂(g)
Define metallic bonding - ANSWER-The electrostatic attraction between a regular array
of positive ions and the sea of delocalised electrons
Define metallic bonding - ANSWER-The electrostatic attraction between a regular array
of positive ions and the sea of delocalised electrons
Define metallic bonding - ANSWER-The electrostatic attraction between a regular array
of positive ions and the sea of delocalised electrons
Define metallic bonding - ANSWER-The electrostatic attraction between a regular array
of positive ions and the sea of delocalised electrons
Describe a test to show whether water is pure - ANSWER-If the sample is pure water it
will boil at 100⁰C
Describe an experiment to show that iron rusts quicker in salt water than rain water -
ANSWER-1) Set up tubes containing iron in rain water and in salt water. 2) Set up
control tube with iron and no water. 3) record mass of nails. 4) leave tubes for same
length of time. 5) measure mass change of nail. 6) repeat experiment
Describe how nitrogen oxides and sulfur dioxide contribute to acid rain - ANSWER-
Nitrogen oxides created in hot car engines and sulfur dioxide released when fossil fuels
are burned combine with water in the atmosphere to form acidic solutions
Describe how nitrogen oxides and sulfur dioxide contribute to acid rain - ANSWER-
Nitrogen oxides created in hot car engines and sulfur dioxide released when fossil fuels
are burned combine with water in the atmosphere to form acidic solutions
Describe how pure salt can be obtained from rock salt - ANSWER-1) Grind rock salt into
a fine powder. 2) Add powder to hot water and stir to dissolve salt. 3) Filter mixture. Salt
solution passes through the filter paper leaving behind the sand. 4) Boil filtrate to
evaporate some of the water. 5) Leave saturated solution to cool so that crystals of salt
form. 6) Filter cold mixture to separate the crystals from the remaining solution.
Describe how you would carry out a flame test - ANSWER-Put solid onto a wire. Put
into a blue flame
Describe how you would test for carbonate ions, CO₃²⁻ - ANSWER-Add nitric acid and
see if carbon dioxide bubbles form
Describe how you would test for Cu²⁺ ions - ANSWER-Add sodium hydroxide and a
blue precipitate will form
, Describe how you would test for Fe²⁺ ions - ANSWER-Add sodium hydroxide and a
green precipitate will form
Describe how you would test for Fe³⁺ ions - ANSWER-Add sodium hydroxide and a
brown precipitate will form
Describe how you would test for sulfate ions - ANSWER-Add dilute HCl, followed by
BaCl₂. A white precipitate will form
Describe the arrangement and movement of the particles in a liquid - ANSWER-
Particles are close together but irregular. The particles are free to move.
Describe the arrangement, movement and energy of the particles in a gas - ANSWER-
Particles are far apart and there are no forces between them. Energy is high. The
particles move quickly and freely.
Describe the arrangement, movement and energy of the particles in a solid - ANSWER-
Particles are close together and regularly packed. Energy is low. The particles vibrate
around a fixed point.
Describe the changes in arrangement, movement and energy of particles when a liquid
cools to become a solid - ANSWER-Arrangement becomes more regular. Particles
vibrates in a fixed position. Particles lose energy
Describe the changes in arrangement, movement and energy of particles when a liquid
turns into a solid - ANSWER-The particles form a regular arrangement, they slow down
and lose kinetic energy
Describe the chemical test for water - ANSWER-Add water to anhydrous copper(II)
sulfate which will change from white to blue if water is present
Describe the conditions under which iron rusts - ANSWER-oxygen and water
Describe the formation of a covalent bond - ANSWER-The sharing of a pair of electrons
between two nuclei
Describe the formation of a covalent bond - ANSWER-The sharing of a pair of electrons
between two nuclei
Describe the formation of a covalent bond - ANSWER-The sharing of a pair of electrons
between two nuclei
Describe the formation of a covalent bond - ANSWER-The sharing of a pair of electrons
between two nuclei
