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?
| 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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A student performs a technique using the apparatus shown.
Which separation technique has the student performed?
Crystallisation
Evaporation
Distillation
Filtration
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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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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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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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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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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.
Which diagram correctly illustrates the filter paper at stage 3?
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The diagram below shows the apparatus a student used to separate a product from a reaction mixture.
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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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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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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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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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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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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