GCSE AQA Chemistry: Tests for Ions (With exam style questions)

Tests for Cations: What colour precipitate does Calcium (Ca²⁺) form when mixed with NaOH?

• White

• Blue

• Green

• Brown

• White at first, But then redissolves with excess NaOH to form a colourless solution.

Tests for Cations: What colour precipitate does Copper II (Cu²⁺) form when mixed with NaOH?

• White

• Blue

• Green

• Brown

• White at first, But then redissolves with excess NaOH to form a colourless solution.

Tests for Cations: What colour precipitate does Iron II (Fe²⁺) form when mixed with NaOH?

• White

• Blue

• Green

• Brown

• White at first, But then redissolves with excess NaOH to form a colourless solution.

Tests for Cations: What colour precipitate does Iron III (Fe³⁺) form when mixed with NaOH?

• White

• Blue

• Green

• Brown

• White at first, But then redissolves with excess NaOH to form a colourless solution.

Tests for Cations: What colour precipitate does Aluminium (Al³⁺) form when mixed with NaOH?

• White

• Blue

• Green

• Brown

• White at first, But then redissolves with excess NaOH to form a colourless solution.

Tests for Cations: What colour precipitate does Magnesium (Mg²⁺) form when mixed with NaOH?

• White

• Blue

• Green

• Brown

• White at first, But then redissolves with excess NaOH to form a colourless solution.

Describe the test for Carbonates (CO₃^2- ions)

• Dilute acid added with pipette, connected with a tube to a test tube of limewater. Positive test if limewater goes cloudy.

• Add drops of dilute hydrochloric acid. Add drops of barium chloride solution. Positive test if white precipitate forms.

• Add drops of dilute nitric acid. Add drops of silver nitrate solution. Different precipitates formed for each Anion.

• Flame test.

• Add sodium hydroxide solution. Different precipitates formed with each Cation.

Describe the test for Sulfates (SO₄^2- ions)

• Dilute acid added with pipette, connected with a tube to a test tube of limewater. Positive test if limewater goes cloudy.

• Add drops of dilute hydrochloric acid. Add drops of barium chloride solution. Positive test if white precipitate forms.

• Add drops of dilute nitric acid. Add drops of silver nitrate solution. Different precipitates formed for each Anion.

• Flame test.

• Add sodium hydroxide solution. Different precipitates formed with each Cation.

Describe the test for Halides (Cl^-, Br^-, I^-)

• Dilute acid added with pipette, connected with a tube to a test tube of limewater. Positive test if limewater goes cloudy.

• Add drops of dilute hydrochloric acid. Add drops of barium chloride solution. Positive test if white precipitate forms.

• Add drops of dilute nitric acid. Add drops of silver nitrate solution. Different precipitates formed for each Anion.

• Flame test.

• Add sodium hydroxide solution. Different precipitates formed with each Cation.

Describe the test for a Cation e.g. Lithium, Potassium.

• Dilute acid added with pipette, connected with a tube to a test tube of limewater. Positive test if limewater goes cloudy.

• Add drops of dilute hydrochloric acid. Add drops of barium chloride solution. Positive test if white precipitate forms.

• Add drops of dilute nitric acid. Add drops of silver nitrate solution. Different precipitates formed for each Anion.

• Flame test.

• Add sodium hydroxide solution. Different precipitates formed with each Cation.