The children in Amazon Class learnt about endothermic and exothermic reactions in science today. The lesson started by thinking about how the reaction in an ice-pack will cause it to become very cold (an endothermic reaction), whereas the chemical reaction in a handwarmer will cause it to heat up (an exothermic reaction).
The children then explored exothermic reactions in more depth by investigating what happens to the temperature of the mixture when Calcium carbonate is added to water. They asked the question: How does the volume of calcium carbonate affect the temperature of water?
A large part of the lesson focused on assessing and mitigating risk. You will notice in the pictures that the children are wearing goggles, aprons and gloves to avoid getting calcium carbonate onto their skin or in their eyes (as it can be an irritant) and that they are using a long-arm-pour technique to keep the reactants away from their faces.
The children were really interested to learn that there is a direct link between the quantity of CaCl2 and the temperature of the water, which on the fifth repetition heated up to more than 400C!
We would like to thank Mr Burroughs with providing us with the idea and some of the equipment from Hartismere High School.
