This week’s kit is all about chemistry! Chemistry is the science of mixing things together and making things change. There are some easy ways to tell if you’ve got a chemical reaction. Some of these inlcude – a colour change, a temperature change (getting hot or cold) or making something new, like bubbles of carbon doxide! In you kit you should have –
Calcium chloride (to be used with adult supervision)
Smelly powder mix
You will need –
A tub, like a takeaway tub or lunchbox
6 cups or pots
3 liquids (e.g water, oil and washing up liquid)
Pour 100ml of water into your tub.
Sprinkle the xanthan gum powder onto the water, making sure it covers most of the surface.
Mix it well with your fork (don’t worry if it’s a bit lumpy!)
Put it in the fridge for 20 minutes.
Take it out of the fridge, you should have a slimey mixture!
Here is Chemical Cress to explain what has happened –
For this experiment you might want to write down your predictions, results and conclusion.
Note: You don’t have to use all of the popping candy in this experiment, it is safe to eat as long as you don’t have a dairy allergy. (Ask a grown-up first)
Popping candy is made of sugar that has been compressed and had bubbles of carbon dioxide squeezed into it. When it gets wet, the sugar starts to dissolve and so the bubbles pop, which is what we hear when we eat it!
Take 3 cups or pots and put a different liquid in each one. These can be liquids of your choice (you can use more than 3 if you wanted to), some examples could be: water, oil, washing up liquid, vinegar. To make it a fair test – measure out each liquid so you have the same amount of each. You don’t need very much – a teaspoon of each will do!
Predict what you think will happen – will the popping candy pop in each liquid? Will it pop more quickly in one?
Sprinkle some popping candy into each liquid, one at a time, listening carefully to each one. To make it more scientific, and a fair test, you could weigh or measure out your popping candy to ensure the same amount is used each time.
What did you find out?
Here is Chemical Cress to explain why popping candy pops differently in different liquids –
*Do this experiment with a grown-up*
When a chemical reaction gets hot we call it an exothermic reaction. The opposite of this, when it takes away heat, is called an endothermic reaction.
Fill a cup 1/4 full with cold water.
Pour the calcium chloride into the water.
Feel underneath the cup, it should start to get warm!
Pour the mixture away (down the drain is fine)
When calcium chloride mixes with water, it releases heat – this is an exothermic reaction.
Fill a cup half full with water.
Pour in your smelly powder mix.
Feel the outside of the cup and sniff the top of it!
Chemical Cress will explain some of the things you may have noticed in this experiment –