When acids react with metals, they produce a salt and hydrogen gas. Most metals react with acids, but not all. The general equation that describes the chemical reaction between an acid and metal is metal + acid = salt + hydrogen gas.
This type of chemical reaction is known as a single displacement reaction, where an element displaces another in a compound. The hydrogen in acids is displaced by the metals to produce hydrogen gas.
The two common acids are sulfuric acid (H2SO4) and hydrochloric acid (HCl). The most active metals are magnesium (Mg), zinc (Zn), iron (Fe) and lead (Pb). The most inactive metals are copper (Cu), silver (Ag) and gold (Au).
Active metals can displace hydrogen ions from acids, while inactive metals cannot. The salt produced when an acid reacts with a metal differs, in that the type of salt produced depends on the type of acid used for the reaction. Sulfuric acid produces sulfate salts, while hydrochloric acid produces chloride salts.
Here are some examples of acid metal chemical reactions:
- Magnesium + hydrochloric acid = magnesium chloride + hydrogen gas (Mg + 2HCl = MgCl2 + H2)
- Magnesium + sulphuric acid = magnesium sulphate + hydrogen (Mg + H2SO4 = MgSO4 + H2)
- Iron + sulfuric acid = iron sulfate + hydrogen (Fe + H2SO4 = FeSO4 + H2)