tests for non-metal ions

Question 1

Carbonate (CO₃²)

Answer 1

• add dilute hydrochloric acid
• bubble any gas produced through lime water

white precipitate forms = contains

Question 2

Sulphate (SO₄²⁻)

Answer 2

• add dilute hydrochloric acid
• add barium chloride solution

white precipitate of barium sulphate forms = contains

Question 3

Chloride (Cl⁻)

Answer 3

• add dilute nitric acid
• add silver nitrate acid

white precipitate that slowly turns purple in sunlight = contains

Question 4

Bromide

Answer 4

• add dilute nitric acid
• add silver nitrate acid

cream precipitate that slowly turns purple in sunlight = contains

Question 5

Nitrate (NO₃⁻)

Answer 5

• add few drops of sodium hydroxide solution and warm
• add aluminium powder
• hold red litmus paper over the test tube

red litmus paper turns blue = contains

Question 6

Ammonium (NH₄⁺)

Answer 6

• add few drops of sodium hydroxide solution and warm
• hold red litmus paper over the test tube

red litmus paper turns blue = contains