Answer :
The reaction in which two or more reactants react with each other to give a single product is known as Combination reaction. e.g. Calcium oxide reacts vigorously with water to produce slaked lime(calcium hydroxide) releasing a large amount of heat. In this reaction, calcium oxide and water combine to form a single product i.e slaked lime \( CaO_{(s)}+H_{2}O \rightarrow Ca{(OH)}_{2}{(aq)}+Heat \)