Aqua ions

• What happens to metal ions in water?

  They become hydrated with H₂O ligands.
• Which metal aqua ions must be known for A-Level specification?

  Iron(II), copper(II), iron(III), aluminium
• What do the metal ions form that helps identify them?

  Coloured precipitates
• How do metal ions behave in solution?

  They are acidic.
• How do 2+ metal ions compare to 3+ metal ions in terms of acidity?

  2+ ions form weaker acidic solutions than 3+ ions.
• Why do 3+ ions dissociate more than 2+ ions?

  They have greater attractive power to OH^- ions.
• What do metal ions react with in a neutralization reaction?

  Sodium hydroxide
• What is formed when metal ions react with sodium hydroxide?

  A salt and water
• What color precipitate does aluminium form?

  White precipitate
• How can the formulas of precipitates be remembered?

  By the number of OH^- substituted equals the ion charge.
• What do these reactions do to the metal ions?

  They hydrolyse the metal ions.
• What property does aluminium salt exhibit?

  It is amphoteric.
• What happens when sodium hydroxide is added in excess to aluminium salt?

  It acts as an acid and is hydrolysed further.
• How do metal ions react with aqueous ammonia?

  They form a salt and ammonium ions.

  
• What occurs when ammonia is added in excess to copper(II) salt?

  It undergoes ligand substitution to form a deep blue solution.
• What do metal 2+ ions react with sodium carbonate to form?

  Insoluble carbonates and water.

  
• How do metal 3+ ions react with sodium carbonate?

  They form a salt, water, and carbon dioxide.
• What happens when metal aqua ions react with Cl^- ions?

  They undergo ligand substitution to form tetrahedral ions.
• What is formed when metal aqua ions react with concentrated hydrochloric acid?

  Tetrahedral ions with four Cl^- ligands.