Colour of hydroxide precipitate when iron (II) reacts
Green
Colour of hydroxide precipitate when iron (III) reacts
Orange-brown
Colour of hydroxide precipitate when copper (II) reacts
Blue
Colour of hydroxide precipitate when Calcium reacts
White
Colour of hydroxide precipitate when zinc reacts
White
How to differenciate between Zinc and calcium precipitates
Add more sodium hydroxide, zinc dissolves fully in excess sodium hydroxide bet calcium doesn’t
How to do hydroxide precipitate test
Add sodium hydroxide to the solution
Colour of precipitate tells the metal present