Separation & Purification (Cambridge O Level Chemistry)

Topic Questions

11 mark

The diagram below illustrates the experimental set-up to carry out distillation. What are the correct labels for points A and B on the condenser?

q3-easy-mcq-12-2-separation-purification-cie-igcse-chemistry

  Point A Point B
A water in water in
B water in water out
C water out water in
D water out water out

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21 mark

A student performs a technique using the apparatus shown. 

q1-paper-1-nov-2020-ocr-gcse-chem

Which separation technique has the student performed?

  • Crystallisation

  • Evaporation

  • Distillation

  • Filtration

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31 mark

Rocksalt is the mineral form of sodium chloride. It is known to commonly contain sodium chloride and sand along with other trace impurities.

A combination of physical changes and separation techniques can be used to produce higher purity sodium chloride and sand.

What is the correct order of physical changes and separation techniques to separate sodium chloride and sand?

  • Melting, filtering, crystallising

  • Melting, filtering

  • Dissolving, filtering, crystallising

  • Dissolving, crystallising

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11 mark

A yellow solid, W is soluble in water. Which method of separation can be used to obtain the solid W from an aqueous solution?

  • Neutralisation

  • Chromatography

  • Distillation

  • Crystallisation

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11 mark

A substance was analysed and was found to have a boiling point of 450 °C.

At room temperature it is a soft grey solid.

Which temperature could be the melting point of a pure sample of the substance?

  • - 12 °C

  • 56 °C to 72 °C

  • 250 °C to 275 °C

  • 142 °C

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21 mark

Solid P melts at exactly 60oC and boils at exactly 310oC. Solid Q dissolves in ethanol and shows a green colour and a yellow colour when analysed using paper chromatography.

Which row is correct?

 

Contains only one substance

Contains more than one substance

A

Q

P

B

Q

-

C

-

Q

D

P

Q

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31 mark

Pure H2O boils at 100 oC and freezes at 0 oC.

What is the melting point and boiling point of water after the addition of potassium chloride?

 

Boiling point / oC

Freezing point / oC

A

103

-3

B

103

3

C

97

-3

D

97

No change

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41 mark

A student has performed an experiment which produced a precipitate. She correctly chooses to separate the precipitate using the process of filtration. She prepares the filter paper to be placed into the funnel by folding it as shown below.

q4-medium-mcq-12-2-separation-purification-cie-igcse-chemistry

Which diagram correctly illustrates the filter paper at stage 3?

q4-2-medium-mcq-12-2-separation-purification-cie-igcse-chemistry

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51 mark

The diagram below shows the apparatus a student used to separate a product from a reaction mixture.

q5-medium-mcq-12-2-separation-purification-cie-igcse-chemistry

What did the mixture contain?

  • Aqueous sodium chloride and unreacted solid catalyst

  • Water and ethanol

  • Water and oil

  • Aqueous sodium chloride and oil

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61 mark

Which property of a liquid ester can be used to check its purity before use as a food flavouring?

  • boiling point

  • colour 

  • smell

  • solubility in water

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71 mark

Which sequence of procedures is used to separate a pure, dry sample of hydrated copper(II) sulfate, CuSO4•5H2O, from a mixture containing hydrated copper(II) sulfate and calcium carbonate, CaCO3?

  • dissolve in water → distillation → crystallisation

  • dissolve in water → filtration → crystallizationv

  • Distillation → crystallisation → heating to remove all water

  • fractional distillation → filtration → heating to remove all water

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81 mark

J is an aqueous solution.

On addition of aqueous sodium hydroxide to J a green precipitate is formed.

The resulting mixture is heated and no gas is formed.

Aluminium foil is added to the warmed mixture. A gas is formed that turns damp red litmus paper blue.

Which ions could be present in J?

  • Fe3+ and NH4+

  • Fe3+ and NO3

  • Fe2+ and NH4+

  • Fe2+ and NO3

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91 mark

Gas X has the following properties.

1

colourless

2 no effect on either damp red or blue litmus papersno effect on either damp red or blue litmus papers
3 no effect on limewaterno effect on limewater
4

flammable

  • ammonia

  • chlorine

  • hydrogen

  • oxygen

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