2.7.1b: recall the reaction of the elements in group 2 with oxygen, chlorine and water

Beryllium is the exception - it reacts with chlorine, but not with oxygen or water

REACTION WITH OXYGEN

React to form the metal oxide

Eg. 2Mg(s) + O2(g) → 2MgO(s)

Metal oxides are ionic compounds consisting of ions with relatively high charges, so they have high melting points

REACTION WITH WATER

Magnesium reacts very slowly with cold water but very quickly with steam to give the metal oxide and hydrogen

• eg. Mg(s) + H2O(g) → MgO(s) + H2(g)

The other elements react with water to give the metal hydroxide and hydrogen

• eg. Ca(s) + 2H2O(l) → Ca(OH)2(s) + H2(g)

REACTION WITH CHLORINE

All group 2 elements react with chlorine to form white solids with the formula MCl2

• eg. Be(s) + Cl2(g) → BeCl2(s)