Still crazy

Is there a limit to how much of a substance will dissolve in water?

Be careful when handling the various substances you choose for this investigation.

Do not drink any of the solutions you produce.

PLAN

Obtain a selection of different substances that you know will dissolve.

Using one substance at a time, gradually add it to the water and stir to dissolve it.

Observe carefully to see when no more of the substance will dissolve.

A solution that is "full up" like this - where no more of a substance can be dissolved in it - is called a saturated solution.

I WILL NEED

A supply of water.

Containers (preferably made of glass - so you can observe what happens).

Stirrer.

Various soluble substances (e.g.: salt, sugar, coffee granules, etc.)

Paper and pencil.

FAIR TEST

Does it matter how much water you use?

Does it matter how long you stir for?

PREDICTION

Which substance will dissolve the most?

PRACTICAL ACTIVITY

Place a certain amount of water in a container.

Add one of the substances bit by bit while stirring the water.

Observe carefully.

Stop adding the substance when no more of it will dissolve.

How much of the substance have you used?

Repeat with different substance.

COLLECT

DATA

How  will you measure the amount of each substance that you have used?

Record clearly and neatly.

ANALYSE

DATA

This should be straight-forward.

PRESENT

FINDINGS

What is the best way to show your findings?

Perhaps you could make an illustrated chart?

EVALUATE

INVESTIGATION

How useful was this investigation?

Are there any changes you could have made to discover even more than you did?

If you have carried out this investigation, click the icon to send in your results to Brainboxx and we may publish your work on the website.  It is best to e-mail the results of your investigation or you may need to send them by post.  Make sure you get permission from a teacher, parent or other adult before you get in touch.

Crystals

Dissolving