Kitchen chemistry – solutions and suspensions – February 2019

In our continuing study of the properties of matter, we’ve been learning about solutions, suspensions, solubility and precipitates. To demonstrate this, and because we needed a break from our usual routine, we had a kitchen science morning, raiding the boys’ IGCSE kit.

We experimented with different chemicals, using some of the tests for cations (positive ions, ie metals). The ones with good colours were the most fun. The idea is that if you were given an unknown substance, you can perform certain chemical tests on it and find out which cation it contains. Like being a chemistry detective.

I love the colour of copper sulphate, so we made some up (a solution), and then added dilute sodium hydroxide. If copper is present, a blue precipitate forms.

Another fun and colourful one is adding sodium hydroxide to a solution containing iron III. If the cation is present a green precipitate forms.

We tried several others, and then Dancing Toes mixed them all together, creating a beautiful, multi coloured concoction!

Then we looked at acids and alkalis and learnt how to use litmus paper.

This picture is of our attempt to make butter. We studied the properties of milk, and one of the experiments suggested was to make butter. It’s really easy; just shaking a jar of  cream until it turns into butter, with a little butter milk made along the way. A good way to while away the time on a short car journey, and then tasty on rolls for lunch!

There is so much to explore and wonder at in our world, and I find it deeply satisfying to have the privilege of facilitating a child’s natural curiosity.