BACK TO WORKSHEETS
You've been studying a lot about different materials, including what happens when you mix them together.
This activity will offer you the opportunity to review what happens when substances are heated, cooled, mixed together and whether or not you can get them back again, separately. In other words, are any of these changes reversible?
You're familiar with changes like melting, boiling and freezing - they are caused by either adding heat or taking it away.
You're also familiar with stirring substances, like salt and sugar, into water to see what happens.
You'll remember that a solution forms from this and if you want to get the dissolved solid back, you're going to have to evaporate the water away.
Meanwhile, if you thought that filtration would work for getting the salt back from salt solution, it won't (the particles of dissolved salt fit through the holes in the filter paper) but that will work when a solid doesn't dissolve well in water - try it with custard powder stirred into water!
OK, so that's a little reminder of what you already knew. Ready to tackle the questions? Let's get involved!
