Test for anions and aqueous cations

What is the test for carbonate?

Add dilute acid.

What is the result if carbonate (CO₃²⁻) reacts with dilute acid?

Effervescence. Carbon dioxide (CO₂) is produced.

What is the test for chloride?

Add dilute nitric acid, then add silver nitrate.

What is the result if chloride (Cl⁻) is present?

White precipitate (AgCl).

What is the test for bromide?

Add dilute nitric acid, then add silver nitrate.

What is the result if bromide (Br⁻) is present?

Cream precipitate (AgBr).

What is the test for iodide?

Add dilute nitric acid, then add silver nitrate.

What is the result if iodide (I⁻) is present?

Yellow precipitate (AgI).

What is the test for nitrate?

Add aqueous sodium hydroxide and aluminium foil. Warm gently.

What is the result if nitrate (NO₃⁻) is present?

Ammonia (NH₃) is produced.

What is the test for sulfate?

Acidify, then add barium nitrate.

What is the result if sulfate (SO₄²⁻) is present?

White precipitate (BaSO₄).

What is the test for sulfite?

Add dilute hydrochloric acid and warm gently.

What is the result if sulfite (SO₃²⁻) is present?

Sulfur dioxide (SO₂) is produced.

What is the result with aqueous sodium hydroxide for aluminium (Al³⁺)?

White precipitate. Soluble in excess to colourless solution.

What is the result with aqueous ammonia for aluminium (Al³⁺)?

White precipitate. Insoluble in excess.

What is the test for ammonium ions?

Add aqueous sodium hydroxide and warm.

What is the result if ammonium (NH₄⁺) is present?

Ammonia (NH₃) is produced.

What is the result with aqueous sodium hydroxide for calcium (Ca²⁺)?

White precipitate. Insoluble in excess.

What is the result with aqueous ammonia for calcium (Ca²⁺)?

No precipitate or very slight white precipitate.

What is the result with aqueous sodium hydroxide for chromium(III) (Cr³⁺)?

Green precipitate. Soluble in excess.

What is the result with aqueous ammonia for chromium(III) (Cr³⁺)?

Grey-green precipitate. Insoluble in excess.

What is the result with aqueous sodium hydroxide for copper(II) (Cu²⁺)?

Light blue precipitate. Insoluble in excess.

What is the result with aqueous ammonia for copper(II) (Cu²⁺)?

Light blue precipitate. Soluble in excess to dark blue solution.

What is the result with aqueous sodium hydroxide for iron(II) (Fe²⁺)?

Green precipitate. Insoluble in excess.

What is the result with aqueous ammonia for iron(II) (Fe²⁺)?

Green precipitate. Insoluble in excess.

What is the result with aqueous sodium hydroxide for iron(III) (Fe³⁺)?

Red-brown precipitate. Insoluble in excess.

What is the result with aqueous ammonia for iron(III) (Fe³⁺)?

Red-brown precipitate. Insoluble in excess.

What is the result with aqueous sodium hydroxide for zinc (Zn²⁺)?

White precipitate. Soluble in excess to colourless solution.

What is the result with aqueous ammonia for zinc (Zn²⁺)?

White precipitate. Soluble in excess to colourless solution.

Describe how to carry out a flame test.

Clean a wire loop with hydrochloric acid. Dip the loop into the solid or solution. Place it in a blue Bunsen flame. Observe the flame colour.

How to test for the presence of water.

Add white anhydrous copper sulfate to substance and if it turns blue water is present. If not it stays white.

What is a physical test to see if water is pure?

Measure the boiling point. Pure water boils at 100C. Fixed boiling point = pure water.