IGCSE CHEMISTRY STUDY GUIDE
PRACTICE EXAM QUESTIONS WITH
CORRECT ANSWERS LATEST UPDATE
GRADED A+
Explain how fractional distillation is used to separate a mixture of
different liquids --ANSWER--The different liquids have different
boiling points
State the method used to extract the red dye from a sample of rose
petals --ANSWER--dissolving
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.
Page 1 of 96
,Ethanol is a flammable liquid. Suggest how it could be heated safely -
-ANSWER--Use a water bath
Explain how a chromatogram shows that different dyes are different
from each other --ANSWER--Each dyes has a different mixture
State the method used to obtain sand from a mixture of sand and
water --ANSWER--filtration
State the method used to obtain solid copper sulfate from aqueous
copper sulfate --ANSWER--crystallisation
State the method used to obtain red food dye from a mixture of food
dyes --ANSWER--paper chromatography
State the method used to obtain water from salt water --ANSWER--
simple distillation
Draw a diagram to show equipment used in simple distillation --
ANSWER--For what process is this equipment used?
Page 2 of 96
,State the method used to obtain kerosene from a crude oil. --
ANSWER--fractional distillation
Draw the equipment used in fractional distillation in the lab --
ANSWER--For what process is this equipment used?
State the expression for calculating molar concentration --ANSWER--
Molar concentration = Amount (in moles)/volume (in dm^³)
Which cation gives a crimson red flame colour? --ANSWER--Li⁺
Which cation gives a orange flame colour? --ANSWER--Na⁺
Which cation gives a lilac flame colour? --ANSWER--K⁺
Which cation gives a brick red flame colour? --ANSWER--Ca²⁺
Page 3 of 96
, Describe how you would carry out a flame test --ANSWER--Put solid
onto a wire. Put into a blue flame
How would you test for the ammonium ion? --ANSWER--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 --ANSWER--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⁺ --ANSWER--
Cu(OH)₂
Describe how you would test for Fe²⁺ ions --ANSWER--Add sodium
hydroxide and a green precipitate will form
Write a word equation for the reaction between sodium hydroxide and
iron(II) sulfate --ANSWER--sodium hydroxide + iron(II) sulfate ->
iron (II) hydroxide + sodium sulfate
Page 4 of 96
PRACTICE EXAM QUESTIONS WITH
CORRECT ANSWERS LATEST UPDATE
GRADED A+
Explain how fractional distillation is used to separate a mixture of
different liquids --ANSWER--The different liquids have different
boiling points
State the method used to extract the red dye from a sample of rose
petals --ANSWER--dissolving
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.
Page 1 of 96
,Ethanol is a flammable liquid. Suggest how it could be heated safely -
-ANSWER--Use a water bath
Explain how a chromatogram shows that different dyes are different
from each other --ANSWER--Each dyes has a different mixture
State the method used to obtain sand from a mixture of sand and
water --ANSWER--filtration
State the method used to obtain solid copper sulfate from aqueous
copper sulfate --ANSWER--crystallisation
State the method used to obtain red food dye from a mixture of food
dyes --ANSWER--paper chromatography
State the method used to obtain water from salt water --ANSWER--
simple distillation
Draw a diagram to show equipment used in simple distillation --
ANSWER--For what process is this equipment used?
Page 2 of 96
,State the method used to obtain kerosene from a crude oil. --
ANSWER--fractional distillation
Draw the equipment used in fractional distillation in the lab --
ANSWER--For what process is this equipment used?
State the expression for calculating molar concentration --ANSWER--
Molar concentration = Amount (in moles)/volume (in dm^³)
Which cation gives a crimson red flame colour? --ANSWER--Li⁺
Which cation gives a orange flame colour? --ANSWER--Na⁺
Which cation gives a lilac flame colour? --ANSWER--K⁺
Which cation gives a brick red flame colour? --ANSWER--Ca²⁺
Page 3 of 96
, Describe how you would carry out a flame test --ANSWER--Put solid
onto a wire. Put into a blue flame
How would you test for the ammonium ion? --ANSWER--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 --ANSWER--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⁺ --ANSWER--
Cu(OH)₂
Describe how you would test for Fe²⁺ ions --ANSWER--Add sodium
hydroxide and a green precipitate will form
Write a word equation for the reaction between sodium hydroxide and
iron(II) sulfate --ANSWER--sodium hydroxide + iron(II) sulfate ->
iron (II) hydroxide + sodium sulfate
Page 4 of 96
