4 Reaction of period 3 oxides with acids and bases

Acid base reactions between period 3 oxides and simple acids and bases. The basic oxides react with acids to make salts Na2O (s) + 2 HCl (aq)
2NaCl (aq) + H2O (l) Na2O (s) + H2SO4 (aq)
Na2SO4 (aq) + H2O (l) MgO (s) + 2 HCl (aq)
MgCl2 (aq) + H2O (l) Or ionically Na2O (s) + 2H+ (aq)
2Na+ (aq) + H2O (l) MgO (s) + 2 H+ (aq)
Mg2+ (aq) + H2O (l) Rather than learning the equations by rote, learn the pattern. Most follow the pattern acid + base = salt + water Know the charges on the ions e.g. PO4 3- , SO4 2- Amphoteric Oxides Aluminium oxide can act as both an acid and an alkali and is therefore called amphoteric Aluminum oxide acting as a base Al2O3 (s)+ 3H2SO4 (aq)
Al2 (SO4 )3 (aq) + 3H2O (l) Al2O3 + 6HCl
2AlCl3 + 3H2O Or ionically Al2O3 + 6H+
2Al3+ + 3H2O Aluminum oxide acting as a acid Al2O3 (s)+ 2NaOH (aq) + 3H2O (l)
2NaAl(OH)4 (aq) (this equation needs learning carefully) Al2O3 (s)+ 2OH- (aq) + 3H2O (l)
2Al(OH)4 – (aq) SiO2 has a giant covalent structure with very strong bonds. This stops SiO2 dissolving or reacting with water and weak solutions of alkali. It will, however, react with very concentrated NaOH 2NaOH (l) + SiO2 (s)
Na2SiO3 (aq) + H2O It is still classed as an acidic oxide The other simple molecular acidic oxides react with bases to form salts. P4O10 (s) + 12 NaOH (aq)
4Na3PO4 (aq) + 6 H2O (l) P4O10 + 6 Na2O
4Na3PO4 SO2 (g) + 2NaOH (aq)
Na2SO3 (aq) + H2O (l) SO3 (g) + 2NaOH(aq)
Na2SO4 (aq) + H2O (l) Or show ionically P4O10 (s) + 12 OH- (aq)
4PO4 3-(aq) + 6 H2O (l) SO2 (g) + 2OH- (aq)
SO3 2- (aq) + H2O (l) SO3 (g) + 2OH- (aq)
SO4 2- (aq) + H2O (l) Be careful for whether the question is asking for an ionic equation or a full one