metal ion tests

• Colour of Al³⁺ precipitate with NaOH?

  white - it dissolves completely in excess
• Colour of Ca²⁺ or Mg²⁺ precipitate with NaOH?

  white
• Colour of Cu²⁺ precipitate with NaOH?

  Blue
• Colour of Fe²⁺ precipitate with NaOH?

  Green
• Colour of Fe³⁺ precipitate with NaOH?

  Brown