IGCSE Chemistry 2026 | Comprehensive
Study Guide, Practice Questions,
Answers, Practical Skills & Exam Review |
Complete Ethics Study
Guide
Updated 2026 Questions and Answers
100% Verified Exam Prep and Comprehensive
Rationales
Included
,State the method used to obtain sand from a mixture of filtration
sand and water
State the method used to obtain solid copper sulfate from crystallisation
aqueous copper sulfate
State the method used to obtain red food dye from a paper chromatography
mixture of food dyes
State the method used to obtain water from salt water simple distillation
Draw a diagram to show equipment used in simple For what process is this equipment used?
distillation
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 The different liquids have different boiling points
mixture of different liquids
State the method used to extract the red dye from a dissolving
sample of rose petals
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 Use a water bath
heated safely
Explain how a chromatogram shows that different dyes are Each dyes has a different mixture
different from each other
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 Cu(OH)₂
sodium hydroxide is added to a solution containing Cu²⁺
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 sodium hydroxide + iron(II) sulfate -> iron (II) hydroxide + sodium sulfate
hydroxide and iron(II) 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 Add dilute nitric acid and silver nitrate. A white precipitate of silver chloride is
ions? What is observed if they are present? 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 A yellow precipitate (of silver iodide) is formed.
containing iodide ions, what colour precipitate is formed?
Why is hydrochloric acid added before barium chloride To remove carbonate ions
solution in testing for sulfate 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 BaCl₂ (aq) + Li₂SO₄ (aq) -> BaSO₄ (s)+ 2LiCl (aq). Observe a white precipitate of
barium chloride and lithium sulfate (Li₂SO₄). Include state barium sulfate.
symbols. Also, what would you see?
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 % yield = (actual amount of products/theoretical amount of products) x100
only!)
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 anhydrous copper sulfate (white) + water <-> hydrated copper sulfate (blue)
used to test for the presence of water. The reaction is
reversible. What is the word equation? Describe the colour
change.
Ammonia and hydrogen chloride react together in a ammonia + hydrogen chloride <-> ammonium chloride NH₃ + HCl <-> NH₄Cl
reversible reaction to produce a white solid. What are the
word and symbol equations?
State two features of a reaction that is in dynamic 1) The rate of the forward reaction is equal to the rate of the backward reaction. 2)
equilibrium There is no overall change in concentrations.
Predict what will happen to the equilibrium position in the Equilibrium will move to the left because there are fewer molecules on the left hand
following reaction when the pressure is increased. Give a side
reason for your prediction: CH₄(g) + H₂O(g) <-> CO(g) +
3H₂(g) ΔH = +210 kJ mol⁻1
Predict what will happen to the equilibrium position in the Equilibrium will move to the right because the forward reaction is endothermic
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
Predict what will happen to the rate of reaction in the The rate will increase
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
Predict what will happen to the equilibrium position in the Equilibrium will move to left the because the reaction is exothermic
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
Study Guide, Practice Questions,
Answers, Practical Skills & Exam Review |
Complete Ethics Study
Guide
Updated 2026 Questions and Answers
100% Verified Exam Prep and Comprehensive
Rationales
Included
,State the method used to obtain sand from a mixture of filtration
sand and water
State the method used to obtain solid copper sulfate from crystallisation
aqueous copper sulfate
State the method used to obtain red food dye from a paper chromatography
mixture of food dyes
State the method used to obtain water from salt water simple distillation
Draw a diagram to show equipment used in simple For what process is this equipment used?
distillation
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 The different liquids have different boiling points
mixture of different liquids
State the method used to extract the red dye from a dissolving
sample of rose petals
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 Use a water bath
heated safely
Explain how a chromatogram shows that different dyes are Each dyes has a different mixture
different from each other
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 Cu(OH)₂
sodium hydroxide is added to a solution containing Cu²⁺
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 sodium hydroxide + iron(II) sulfate -> iron (II) hydroxide + sodium sulfate
hydroxide and iron(II) 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 Add dilute nitric acid and silver nitrate. A white precipitate of silver chloride is
ions? What is observed if they are present? 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 A yellow precipitate (of silver iodide) is formed.
containing iodide ions, what colour precipitate is formed?
Why is hydrochloric acid added before barium chloride To remove carbonate ions
solution in testing for sulfate 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 BaCl₂ (aq) + Li₂SO₄ (aq) -> BaSO₄ (s)+ 2LiCl (aq). Observe a white precipitate of
barium chloride and lithium sulfate (Li₂SO₄). Include state barium sulfate.
symbols. Also, what would you see?
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 % yield = (actual amount of products/theoretical amount of products) x100
only!)
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 anhydrous copper sulfate (white) + water <-> hydrated copper sulfate (blue)
used to test for the presence of water. The reaction is
reversible. What is the word equation? Describe the colour
change.
Ammonia and hydrogen chloride react together in a ammonia + hydrogen chloride <-> ammonium chloride NH₃ + HCl <-> NH₄Cl
reversible reaction to produce a white solid. What are the
word and symbol equations?
State two features of a reaction that is in dynamic 1) The rate of the forward reaction is equal to the rate of the backward reaction. 2)
equilibrium There is no overall change in concentrations.
Predict what will happen to the equilibrium position in the Equilibrium will move to the left because there are fewer molecules on the left hand
following reaction when the pressure is increased. Give a side
reason for your prediction: CH₄(g) + H₂O(g) <-> CO(g) +
3H₂(g) ΔH = +210 kJ mol⁻1
Predict what will happen to the equilibrium position in the Equilibrium will move to the right because the forward reaction is endothermic
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
Predict what will happen to the rate of reaction in the The rate will increase
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
Predict what will happen to the equilibrium position in the Equilibrium will move to left the because the reaction is exothermic
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
