7H7HSummary

2 of 46 © Boardworks Ltd 2008

What is a solution?

A solution is a special type of mixture that is made when one substance dissolves and mixes fully with another.

For example, a cup of instant coffee is a solution.

The solid that dissolves (e.g. coffee granules) is called the solute.

The liquid that does the dissolving (e.g. hot water) is called the solvent.

How many other solutions can you think of?

3 of 46 © Boardworks Ltd 2008

Mixture or solution?

4 of 46 © Boardworks Ltd 2008

Dissolving in action?

5 of 46 © Boardworks Ltd 2008

+

50 g 10 g+

Conservation of mass

If 10 g of salt is added to 50 g of pure water, what is the mass of the solution?

When the salt has dissolved, you can’t see it any more. How could you check that the salt is still there?

?60 g

6 of 46 © Boardworks Ltd 2008

How could you separate these mixtures?

Suggest some methods by which you could separate out these mixtures:

chocolate buttons and raisins

different coloured sweets

pebbles and sand

salt and sand

mud and water

oil and water

gold and iron.

7 of 46 © Boardworks Ltd 2008

Filtering apparatus

8 of 46 © Boardworks Ltd 2008

Evaporation apparatus

9 of 46 © Boardworks Ltd 2008

Chromatography experiment

10 of 46 © Boardworks Ltd 2008

Which separation technique?