Metals with Water and Acids — The Reactivity Series | IGCSE Chemistry

Exam Frequency Analysis

Past paper frequency (2018 to 2024)

This topic accounts for approximately 6% of your exam marks.

stable

Low

Stable6%

Displacement reactions and determining order of reactivity from experimental data.

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

metal + steam → metal oxide + hydrogen

Metal	Behaviour with water
Potassium	Reacts violently with cold water; ignites the hydrogen with a lilac flame
Sodium	Reacts vigorously with cold water; melts to a silvery ball and fizzes
Lithium	Reacts steadily with cold water; floats, fizzes, dissolves
Calcium	Reacts fairly briskly with cold water; produces a cloudy white suspension of Ca(OH)₂
Magnesium	Reacts very slowly with cold water; reacts much faster with steam
Zinc	Only reacts with steam, slowly
Iron	Only reacts with steam, slowly
Copper, silver, gold	No visible reaction with water or steam

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

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)