Activity 1.4

Activity . Take a small amount of calcium oxide or quick lime in a beaker. Slowly add water to this. Touch the beaker as shown in Fig. . . Do you feel any change in temperature? Figure . Figure . Figure . Figure . Figure . Formation of slaked lime by the reaction of calcium oxide with water Calcium oxide reacts vigorously with water to produce slaked lime (calcium hydroxide) releasing a large amount of heat. CaO(s) H O(l) → Ca(OH) (aq) + Heat ( . ) (Quick lime) (Slaked lime) In this reaction, calcium oxide and water combine to form a single product, calcium hydroxide. Such a reaction in which a single product is formed from two or more reactants is known as a combination reaction.