A combination reaction (also known as a synthesis reaction) is a reaction where two or more elements or compounds (reactants) combine to form a single compound (product). Such reactions may be represented by equations of the following form: X + Y → XY.
Combination reactions can involve different types of reactants:
Type | Example | |
a) Between elements | C + O2 → CO2 | Carbon completely burnt in oxygen yields carbon dioxide |
b) Between compounds | CaO + H2O → Ca(OH)2 | Calcium oxide (lime) combined with water gives calcium hydroxide (slaked lime) |
c) Between elements and compounds | 2CO + O2 → 2CO2 | Oxygen combines with carbon monoxide, and carbon dioxide is formed. |