A demonstration of slaking of quicklime as a strongly exothermic reaction. Drops of water are added to pieces of quicklime. After a while, a pronounced exothermic reaction occurs ('slaking of lime') that can be described by the equation: CaO(s) ➕ H2O(l) ⟶ Ca(OH)2(s). The temperature can reach up to some 300 °С.