Sodium hydroxide to identify metal ions

Which metal ion does NOT form a white precipitate when sodium hydroxide solution is added?

• Magnesium
• Calcium
• Aluminium
• Copper(II)

What happens to the aluminium hydroxide precipitate in excess sodium hydroxide solution?

• It forms a brown precipitate
• It dissolves
• It turns green
• It remains unchanged

Which metal ion forms a brown precipitate when sodium hydroxide solution is added?

• Magnesium
• Copper(II)
• Iron(II)
• Iron(III)

Which metal ion forms a green precipitate when sodium hydroxide solution is added?

• Iron(II)
• Iron(III)
• Calcium
• Copper(II)

What is the relationship between the metal ions and the color of their precipitates in sodium hydroxide solution?

• It is random
• The color changes over time
• There is no relationship
• Each metal ion has a specific color precipitate

What colour precipitate does Copper(II) form when sodium hydroxide solution is added?

• White
• Blue
• Green
• Brown

What color precipitate does magnesium form when sodium hydroxide solution is added?

• Blue
• Green
• White
• Brown

What color precipitate does calcium form when sodium hydroxide solution is added?

• Brown
• Green
• Blue
• White