2H2 were learning about exothermic and endothermic reactions today.
We carried out an experiment with sugar and concentrated sulphuric acid as an example of an exothermic reaction:
Next, we demonstrated an endothermic reaction with barium hydroxide and ammonium nitrate. The conical flask got so cold that when placed on a wooden block with a puddle of water, the water froze, sticking the flask to the wood:
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