IGCSE CHEMISTRY EXAM QUESTIONS AND ANSWERS GRADED A+
State the method used to obtain sand from
a mixture of sand and water - correct answer
filtration
State the method used to obtain solid
copper sulfate from aqueous copper sulfate
- correct answer crystallisation
State the method used to obtain red food
dye from a mixture of food dyes - correct answer
paper chromatography
,IGCSE CHEMISTRY EXAM
State the method used to obtain water from
salt water - correct answer simple distillation
Draw a diagram to show equipment used in
simple distillation - correct answer For what
process is this equipment used?
State the method used to obtain kerosene
from a crude oil. - correct answer fractional
distillation
Draw the equipment used in fractional
distillation in the lab - correct answer For what
process is this equipment used?
Explain how fractional distillation is used to
separate a mixture of different liquids - correct
,IGCSE CHEMISTRY EXAM
answerThe different liquids have different
boiling points
State the method used to extract the red
dye from a sample of rose petals - correct answer
dissolving
Describe how pure salt can be obtained
from rock salt - correct 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.
, IGCSE CHEMISTRY EXAM
Ethanol is a flammable liquid. Suggest how
it could be heated safely - correct answer Use a
water bath
Explain how a chromatogram shows that
different dyes are different from each other
- correct answer Each dyes has a different mixture
State the expression for calculating molar
concentration - correct answer Molar
concentration = Amount (in moles)/volume
(in dm^³)
Which cation gives a crimson red flame
colour? - correct answer Li⁺