2      A B C D   Salt seems to disappear if you stir it into water. Which statement is true?
A    The salt dissolves because it is insoluble.
B    The salt dissolves because it is soluble.
C    The salt melts because it is soluble.
D    The salt melts because it is insoluble.

3     A B C D   When you add salt to water:
A    the salt is the solvent.
B    the water is the solute.
C    the salt is the solute.
D   the water is the solution.

4      A B C D   Filtering cannot be used to separate:
A    sand from a mixture of sand and water.
B    sugar from sugar solution.
C    tea leaves from a pot of tea.
D    leaves from a mixture of leaves and pond water.

7Hb
5      A B C D   Most water has chemicals dissolved in it because:
A    it is pure.
B    rain water has lots of chemicals dissolved in it.
C    the water dissolves chemicals from rocks it passes through.
D    the water dissolves chemicals from the pipes it flows through.

6      A B C D   A solid dissolved in water can be obtained by:
A    evaporating the liquid.
B    using a sieve.
C    using a filter.
D    freezing the liquid.

7      A B C D   Which of these cannot be used to make salt?
A    sea water B          salt solution
C    brine D    sugar solution

8      A B C D   Which sentence is not true?
A    Rock salt is a mixture of rock and salt.
B    Rock salt can be used to make pure salt to put on food.
C    You can get salt from rock salt using a sieve.
D    You can get salt from rock salt by dissolving, filtering and evaporating.

7Hc
9      A B C D   Pure water is:
A    water which is clean enough to drink.
B    water which runs off the hills.
C    rain.
D    water with nothing dissolved in it.

10      A B C D   Pure water can be made from inky water by:
A    filtering it.
B    evaporating it.
C    distilling it.
D    adding more water to it.

11      A B C D   The two steps in distillation are:
A    filtering followed by evaporation.
B    evaporation followed by condensation.
C    condensation followed by filtering.
D    filtering followed by condensation.

12      A B C D   Distillation can not be used to separate:
A    sand from sugar.
B    petrol from crude oil.
C    pure water from sea water.
D    alcohol during the production of whisky.

7Hd
13      A B C D   Chromatography is:
A    a way of separating different liquids from each other.
B    a way of separating different dissolved colours from each other.
C    a way to separate a liquid from a solid which doesn’t dissolve.
D    a special way to draw a graph.

14      A B C D   Chromatography will only work if:
A    a lot of each chemical is used.
B    the special paper has been warmed before it is used.
C    the special paper is moved during the experiment.
D    the chemicals to be separated dissolve in the liquid used.

15      A B C D   The diagram shows a chromatogram. Which two chemicals are the same?

     

A    A and B    B          C and B
C    D and F    D          A and G

16      A B C D   Which of these does not involve chromatography?
A    making petrol from oil
B    DNA fingerprinting
C    drugs testing in athletes
D    identifying the food dye in orange squash

7He
17      A B C D   A saturated solution:
A    is always cold.
B    has a lot of water in it.
C    will not dissolve any more solvent.
D    will not dissolve any more solute.

18      A B C D   You can tell if a solution is saturated because:
A    it will be transparent.
B    there will be bits of undissolved solid in it.
C    it will be coloured.
D    it will be hot.

19      A B C D   Only 20 g of a salt will dissolve in 100 g of water at room temperature. If you use hot water instead:
A    less than 20 g will dissolve.
B    only 20 g will dissolve.
C    more than 20 g will dissolve.
D    no salt will dissolve.

20      A B C D   The solubility of a substance is:
A    the mass of solute that will dissolve in 100cm3 water.
B    the mass of solvent that will dissolve in 100cm3 water.
C    the volume of water that 100g of solute will dissolve in.
D    the volume of water that 100g of solvent will dissolve in.

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