Objective – Combination reaction with heat change.
Inference – Calcium oxide (CaO) reacts vigorously with water and form a single product, calcium hydroxide (slaked lime).
CaO(s) + H2O (l) → Ca(OH)2 (s) + Heat
This reaction is an example of combination reaction which liberates a large amount of heat (exothermic reaction). So, when the beaker is touched from outside, it feels hot.
Conclusion – In combination reactions, two or more reactants combine to form a single product.