Combination reactions
Consider the first reaction of activity 16.2. There magnesium reacts with the oxygen in the air to form magnesium oxide.
magnesium + oxygen → magnesium oxide
2Mg + O2 → 2MgO
Here two elements have combined to form a new compound.
Combination reaction
Element with element, element with compound, or compound with compound combining to form a new compound is called a chemical combination reaction.
A + B → C
Three more examples
hydrogen + chlorine → hydrogen chloride
H2 + Cl2 → 2HCl
carbon dioxide + carbon → carbon monoxide
CO2 + C → 2CO
calcium oxide + water → calcium hydroxide
CaO + H2O → Ca(OH)2
How to spot one
A combination reaction always has exactly one product. If there is only one substance on the right-hand side, it is a combination.
Keep CO2 + C → 2CO in mind — we meet it again when we come to the extraction of iron.