Tests for Anions

How do we do a Hallide Ion test?

1. Acidify sample with Nitric Acid (Removing CO₃^2-)

2. Add Silver Nitrate solution (Form precipitate)

3. Silver Halide precipitate will form if ion is present

What are Hallides?

Hallides are anions formed from Noble gases

What colour does Chloride go?

White

What colour does Bromide go?

Cream

What colour does Iodide go?

Yellow

How do we do a Sulfate Ions test?

1. Acidify sample with dilute Hydrochloric Acid (Removing CO₃^2-)

2. Add a few drops of Barium Chloride (forms white solution)

3. White precipitate of Barium Sulfate formed if positive

How do we test for CO₃^2- (Carbonate)?

1. Add dilute hydrochloric acid

2. Bubble released gas through limewater

3. If it is cloudy then carbonate ions are present forming a white precipitate of calcium carbonate