IGCSE Geography – GEO-IGCSE-04 – Complete
Revision Notes on Population, Settlement, Natural
Hazards, Rivers, Coasts, Agriculture, Industry &
Development
State the method used to obtain sand from a mixture of sand and water - filtration
State the method used to obtain solid copper sulfate from aqueous copper sulfate -
crystallisation
State the method used to obtain red food dye from a mixture of food dyes - paper
chromatography
State the method used to obtain water from salt water - simple distillation
Draw a diagram to show equipment used in simple distillation - For what process is this equipment
used?
State the method used to obtain kerosene from a crude oil. - fractional distillation
Draw the equipment used in fractional distillation in the lab - For what process is this equipment
used?
Explain how fractional distillation is used to separate a mixture of different liquids - The different
liquids have different boiling points
State the method used to extract the red dye from a sample of rose petals - dissolving
Describe how pure salt can be obtained from rock salt - 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.
Ethanol is a flammable liquid. Suggest how it could be heated safely - Use a water bath
Explain how a chromatogram shows that different dyes are different from each other - Each dyes has
a different mixture
State the expression for calculating molar concentration - Molar concentration = Amount (in
moles)/volume (in dm^³)
Which cation gives a crimson red flame colour? - Li⁺ Which cation gives a orange flame
colour? - Na⁺
Which cation gives a lilac flame colour? - K⁺ Which cation gives a brick red flame colour? -
Ca²⁺
Describe how you would carry out a flame test - Put solid onto a wire. Put into a blue flame
,How would you test for the ammonium ion? - Add sodium hydroxide. If ammonium ions were
present, ammonia gas will form which will turn damp red litmus paper blue
Describe how you would test for Cu²⁺ ions - Add sodium hydroxide and a blue precipitate will
form
Give the formula of the blue precipitate formed when sodium hydroxide is added to a solution
containing Cu²⁺ - Cu(OH)₂
Describe how you would test for Fe²⁺ ions - Add sodium hydroxide and a green precipitate will
form
Write a word equation for the reaction between sodium hydroxide and iron(II) sulfate - sodium
hydroxide + iron(II) sulfate -> iron (II) hydroxide + sodium sulfate
Describe how you would test for Fe³⁺ ions - Add sodium hydroxide and a brown precipitate will
form
What 2 things are added to a solution to test for chloride ions? What is observed if they are present?
- Add dilute nitric acid and silver nitrate. A white precipitate of silver chloride is formed.
Describe the test for bromide ions. - Add dilute nitric acid and silver nitrate. A cream precipitate of
silver bromide is formed.
After adding nitric acid and silver nitrate to a solution containing iodide ions, what colour precipitate
is formed? - A yellow precipitate (of silver iodide) is formed.
Why is hydrochloric acid added before barium chloride solution in testing for sulfate ions? - To
remove carbonate ions
Describe how you would test for sulfate ions - Add dilute HCl, followed by BaCl₂. A white precipitate
will form
Write an chemical equation for the reaction between barium chloride and lithium sulfate (Li₂SO₄).
Include state symbols. Also, what would you see? - BaCl₂ (aq) + Li₂SO₄ (aq) -> BaSO₄ (s)+ 2LiCl (aq).
Observe a white precipitate of barium sulfate.
Describe how you would test for carbonate ions, CO₃²⁻ - Add nitric acid and see if carbon dioxide
bubbles form
Describe the test for ammonia gas - Turns damp red litmus paper blue
State the expression for calculating % yield. (Triple science only!) - % yield = (actual amount of
products/theoretical amount of products) x100
Describe the chemical test for water - Add water to anhydrous copper(II) sulfate which will change
from white to blue if water is present
What is the symbol for a reversible reaction? -
The addition of water to anhydrous copper sulfate can be used to test for the presence of water. The
reaction is reversible. What is the word equation? Describe the colour change. - anhydrous copper
sulfate (white) + water <-> hydrated copper sulfate (blue)
, Ammonia and hydrogen chloride react together in a reversible reaction to produce a white solid.
What are the word and symbol equations? - ammonia + hydrogen chloride <-> ammonium chloride
NH₃ + HCl <-> NH₄Cl
State two features of a reaction that is in dynamic equilibrium - 1) The rate of the forward reaction is
equal to the rate of the backward reaction. 2) There is no overall change in concentrations.
Predict what will happen to the equilibrium position in the following reaction when the pressure is
increased. Give a reason for your prediction: CH₄(g) + H₂O(g) <-> CO(g) + 3H₂(g) ΔH = +210 kJ mol⁻1 -
Equilibrium will move to the left because there are fewer molecules on the left hand side
Predict what will happen to the equilibrium position in the following reaction when the temperature
is increased. Give a reason for your prediction: CH₄(g) + H₂O(g) <-> CO(g) + 3H₂(g) ΔH = +210 kJ mol⁻1
- Equilibrium will move to the right because the forward reaction is endothermic
Predict what will happen to the rate of reaction in the following reaction when the temperature and
pressure is increased. Give a reason for your prediction: CH₄(g) + H₂O(g) <-> CO(g) + 3H₂(g) ΔH = +210
kJ mol⁻1 - The rate will increase
Predict what will happen to the equilibrium position in the following reaction when the temperature
is increased. Give a reason for your prediction: CO(g) + H₂O(g) <-> CO₂(g) + H₂(g) ΔH = -42 kJ mol⁻1 -
Equilibrium will move to left the because the reaction is exothermic
Predict what will happen to the equilibrium position in the following reaction when the temperature
is decreased. Give a reason for your prediction: CO(g) + 2H₂(g) <-> CH₃OH(g) ΔH = -91 kJ mol⁻1 -
Equilibrium will move to right the because the reaction is exothermic
Predict what will happen to the equilibrium position in the following reaction when the pressure is
decreased. Give a reason for your prediction: CO(g) + 2H₂(g) <-> CH₃OH(g) ΔH = -91 kJ mol⁻1 -
Equilibrium will move to left the because there are more molecules on the left hand side
State the raw materials used in the manufacture of ammonia - nitrogen from air and hydrogen from
natural gas
State a use for N₂ - making ammonia
The following reaction is used to manufacture ammonia in the Haber process: N₂ + 3H₂ -> 2NH₃ ΔH =
-92KJ/mol. The reaction is carried out at 450⁰C but the reaction would be faster if a higher
temperature were used. Suggest why a higher temperature is not used in the Haber process - Yield
would decrease and energy costs would increase
State the temperature used for the manufacture of ammonia by the Haber process - 450°C
State the pressure used for the manufacture of ammonia by the Haber process - 200 atm
State the catalyst used for the manufacture of ammonia by the Haber process - Iron
How is ammonia separated from unreacted hydrogen and nitrogen in the Haber process? - The
reaction mixture is cooled until the ammonia condenses into a liquid
What happens to the unreacted hydrogen and nitrogen in the Haber process? - Recycled
State the uses of ammonia - manufacture of nitric acid and fertilisers
Revision Notes on Population, Settlement, Natural
Hazards, Rivers, Coasts, Agriculture, Industry &
Development
State the method used to obtain sand from a mixture of sand and water - filtration
State the method used to obtain solid copper sulfate from aqueous copper sulfate -
crystallisation
State the method used to obtain red food dye from a mixture of food dyes - paper
chromatography
State the method used to obtain water from salt water - simple distillation
Draw a diagram to show equipment used in simple distillation - For what process is this equipment
used?
State the method used to obtain kerosene from a crude oil. - fractional distillation
Draw the equipment used in fractional distillation in the lab - For what process is this equipment
used?
Explain how fractional distillation is used to separate a mixture of different liquids - The different
liquids have different boiling points
State the method used to extract the red dye from a sample of rose petals - dissolving
Describe how pure salt can be obtained from rock salt - 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.
Ethanol is a flammable liquid. Suggest how it could be heated safely - Use a water bath
Explain how a chromatogram shows that different dyes are different from each other - Each dyes has
a different mixture
State the expression for calculating molar concentration - Molar concentration = Amount (in
moles)/volume (in dm^³)
Which cation gives a crimson red flame colour? - Li⁺ Which cation gives a orange flame
colour? - Na⁺
Which cation gives a lilac flame colour? - K⁺ Which cation gives a brick red flame colour? -
Ca²⁺
Describe how you would carry out a flame test - Put solid onto a wire. Put into a blue flame
,How would you test for the ammonium ion? - Add sodium hydroxide. If ammonium ions were
present, ammonia gas will form which will turn damp red litmus paper blue
Describe how you would test for Cu²⁺ ions - Add sodium hydroxide and a blue precipitate will
form
Give the formula of the blue precipitate formed when sodium hydroxide is added to a solution
containing Cu²⁺ - Cu(OH)₂
Describe how you would test for Fe²⁺ ions - Add sodium hydroxide and a green precipitate will
form
Write a word equation for the reaction between sodium hydroxide and iron(II) sulfate - sodium
hydroxide + iron(II) sulfate -> iron (II) hydroxide + sodium sulfate
Describe how you would test for Fe³⁺ ions - Add sodium hydroxide and a brown precipitate will
form
What 2 things are added to a solution to test for chloride ions? What is observed if they are present?
- Add dilute nitric acid and silver nitrate. A white precipitate of silver chloride is formed.
Describe the test for bromide ions. - Add dilute nitric acid and silver nitrate. A cream precipitate of
silver bromide is formed.
After adding nitric acid and silver nitrate to a solution containing iodide ions, what colour precipitate
is formed? - A yellow precipitate (of silver iodide) is formed.
Why is hydrochloric acid added before barium chloride solution in testing for sulfate ions? - To
remove carbonate ions
Describe how you would test for sulfate ions - Add dilute HCl, followed by BaCl₂. A white precipitate
will form
Write an chemical equation for the reaction between barium chloride and lithium sulfate (Li₂SO₄).
Include state symbols. Also, what would you see? - BaCl₂ (aq) + Li₂SO₄ (aq) -> BaSO₄ (s)+ 2LiCl (aq).
Observe a white precipitate of barium sulfate.
Describe how you would test for carbonate ions, CO₃²⁻ - Add nitric acid and see if carbon dioxide
bubbles form
Describe the test for ammonia gas - Turns damp red litmus paper blue
State the expression for calculating % yield. (Triple science only!) - % yield = (actual amount of
products/theoretical amount of products) x100
Describe the chemical test for water - Add water to anhydrous copper(II) sulfate which will change
from white to blue if water is present
What is the symbol for a reversible reaction? -
The addition of water to anhydrous copper sulfate can be used to test for the presence of water. The
reaction is reversible. What is the word equation? Describe the colour change. - anhydrous copper
sulfate (white) + water <-> hydrated copper sulfate (blue)
, Ammonia and hydrogen chloride react together in a reversible reaction to produce a white solid.
What are the word and symbol equations? - ammonia + hydrogen chloride <-> ammonium chloride
NH₃ + HCl <-> NH₄Cl
State two features of a reaction that is in dynamic equilibrium - 1) The rate of the forward reaction is
equal to the rate of the backward reaction. 2) There is no overall change in concentrations.
Predict what will happen to the equilibrium position in the following reaction when the pressure is
increased. Give a reason for your prediction: CH₄(g) + H₂O(g) <-> CO(g) + 3H₂(g) ΔH = +210 kJ mol⁻1 -
Equilibrium will move to the left because there are fewer molecules on the left hand side
Predict what will happen to the equilibrium position in the following reaction when the temperature
is increased. Give a reason for your prediction: CH₄(g) + H₂O(g) <-> CO(g) + 3H₂(g) ΔH = +210 kJ mol⁻1
- Equilibrium will move to the right because the forward reaction is endothermic
Predict what will happen to the rate of reaction in the following reaction when the temperature and
pressure is increased. Give a reason for your prediction: CH₄(g) + H₂O(g) <-> CO(g) + 3H₂(g) ΔH = +210
kJ mol⁻1 - The rate will increase
Predict what will happen to the equilibrium position in the following reaction when the temperature
is increased. Give a reason for your prediction: CO(g) + H₂O(g) <-> CO₂(g) + H₂(g) ΔH = -42 kJ mol⁻1 -
Equilibrium will move to left the because the reaction is exothermic
Predict what will happen to the equilibrium position in the following reaction when the temperature
is decreased. Give a reason for your prediction: CO(g) + 2H₂(g) <-> CH₃OH(g) ΔH = -91 kJ mol⁻1 -
Equilibrium will move to right the because the reaction is exothermic
Predict what will happen to the equilibrium position in the following reaction when the pressure is
decreased. Give a reason for your prediction: CO(g) + 2H₂(g) <-> CH₃OH(g) ΔH = -91 kJ mol⁻1 -
Equilibrium will move to left the because there are more molecules on the left hand side
State the raw materials used in the manufacture of ammonia - nitrogen from air and hydrogen from
natural gas
State a use for N₂ - making ammonia
The following reaction is used to manufacture ammonia in the Haber process: N₂ + 3H₂ -> 2NH₃ ΔH =
-92KJ/mol. The reaction is carried out at 450⁰C but the reaction would be faster if a higher
temperature were used. Suggest why a higher temperature is not used in the Haber process - Yield
would decrease and energy costs would increase
State the temperature used for the manufacture of ammonia by the Haber process - 450°C
State the pressure used for the manufacture of ammonia by the Haber process - 200 atm
State the catalyst used for the manufacture of ammonia by the Haber process - Iron
How is ammonia separated from unreacted hydrogen and nitrogen in the Haber process? - The
reaction mixture is cooled until the ammonia condenses into a liquid
What happens to the unreacted hydrogen and nitrogen in the Haber process? - Recycled
State the uses of ammonia - manufacture of nitric acid and fertilisers
