Calcium oxide reacts vigorously with water to produce slaked lime CaO(s)+H2O(l)→Ca(OH)2(aq) this reaction can be classified as:
In the given reaction.
CaO(s) + H2O(l) → Ca(OH)2(aq)
Calcium oxide Water Calcium hydroxide
Part i) : lime (CaO) combines with water to form slaked lime Ca(OH)2(aq). Hence two substances are combined to form a single substance, therefore it is a combination reaction.
Part ii): When lime is treated with water, lots of energy is evolved, therefore it is an exothermic reaction.
Therefore, the above reaction is classified as both combination and exothermic reaction.