The Reactivity Series

Metals with water

• Metals high in reactivity react with cold water; metals lower down only react with steam (if at all)
• The general reaction with cold water is:

metal + water → metal hydroxide + hydrogen

• The general reaction with steam is:

metal + steam → metal oxide + hydrogen

• Calcium example:

Ca(s) + 2 H₂O(l) → Ca(OH)₂(aq) + H₂(g)

Metals with dilute acids

• A metal will react with a dilute acid only if it sits above hydrogen in the reactivity series
• The general reaction is:

metal + acid → salt + hydrogen

• The more reactive the metal, the more vigorously it reacts; the metals above sodium are too dangerous to react with acid in a school lab
• The salt formed depends on the acid (chloride from HCl, sulfate from H₂SO₄, nitrate from HNO₃)