5.2 Separating mixtures

Orange squash is a mixture because:

• it is safe to drink.

• it always contains the same proportions of each ingredient.

• it has a number of different ingredients which can be in different amounts.

• it is a single pure substance which cannot be split up.

How can the different liquids in a mixture be separated?

• distillation

• crystallisation

• filtration

• chromatography

How could you separate a mixture of iron and sulphur?

• filtering

• using a sieve

• evaporation

• using a magnet

The melting point of a pure substance is:

• the same as the freezing point.

• the same as the boiling point.

• lower than the freezing point.

• higher than the boiling point.

Which row in the table shows the correct freezing and boiling points for water?

• A

• B

• C

• D

If you add impurities to a substance, what happens to the melting and boiling points?

• A

• B

• C

• D

Filtering separates:

• a liquid from a solution

• two solids in a mixture

• a solid from a liquid

• two liquids in a mixture.

In the apparatus diagram, what is part ‘X’?

• filter funnel

• filter paper

• conical flask

• a mistake in the drawing

What does ‘insoluble’ mean?

• a solid substance that won’t dissolve in a liquid

• a liquid that doesn’t dissolve any solids

• a solid substance that dissolves in a liquid

• any substance that does not dissolve

What do you see when a solid dissolves in a liquid?

• the solid disappears

• the solid sinks to the bottom of the liquid

• the liquid evaporates

• the liquid changes colour