How could you use the number and type of reactants to identify a type of chemical reaction?

There are six types of chemical reactions. Each type can usually be identified by the number and types of reactants:

1. A synthesis or combination reaction has two or more reactants, usually elements. These form one product. For example:

`2 Mg + O_2 -> 2 MgO`

2. A decompostion reaction has only one reactant. It breaks down into two or more products. Example:

`2 H_2O_2 -> 2 H_2O + O_2`

3. A single replacement reaction has two reactants, an element and an ionic compound. The element replaces an element in the compound, producing a different compound and element. Example:

`Zn + CuCl_2 -> ZnCl_2 + Cu`

4.  A double replacement reaction has two ionic compounds as reactants and as products. The ions switch places:

`NaCl_((aq)) + AgNO3_((aq)) -> AgCl_((s)) + NaCl_((aq))`

5. A combustion reaction has a hydrocarbon and oxygen as reactants. Its products are carbon dioxide and water. Example:

`CH_4 + 2 O_2 -gt CO_2 + 2 H_2O `

6. An acid-base reaction is a type of double replacement reaction in which the reactants are an acid (contains the H+ ion) and a base (contains an OH- ion). It produces water and a salt. Example:

`KOH + HCl -> H_2O + KCl`