Identify the cation and anion for the following compounds using qualitative analysis tests and describe the observations.

Here is the completed table for question 22:

• a) Copper(II) Chloride

  • Identification of cation (Cu²⁺): Test: Add aqueous sodium hydroxide (NaOH). Observation: A blue precipitate forms, which is insoluble in excess NaOH.
  • Identification of anion (Cl⁻): Test: Add dilute nitric acid (HNO₃) followed by aqueous silver nitrate (AgNO₃). Observation: A white precipitate forms, which is soluble in dilute aqueous ammonia.

• b) Iron(II) sulphate

  • Identification of cation (Fe²⁺): Test: Add aqueous sodium hydroxide (NaOH). Observation: A green precipitate forms, which is insoluble in excess NaOH.
  • Identification of anion (SO₄²⁻): Test: Add dilute hydrochloric acid (HCl) followed by aqueous barium chloride (BaCl₂). Observation: A white precipitate forms, which is insoluble in excess dilute HCl.

• c) Iron(III) bromide

  • Identification of cation (Fe³⁺): Test: Add aqueous sodium hydroxide (NaOH). Observation: A reddish-brown precipitate forms, which is insoluble in excess NaOH.
  • Identification of anion (Br⁻): Test: Add dilute nitric acid (HNO₃) followed by aqueous silver nitrate (AgNO₃). Observation: A cream precipitate forms, which is sparingly soluble in dilute aqueous ammonia.

• d) Ammonium hydroxide

  • Identification of cation (NH₄⁺): Test: Add aqueous sodium hydroxide (NaOH) and warm gently. Observation: A pungent gas is evolved, which turns damp red litmus paper blue.
  • Identification of anion (OH⁻): Test: Test the solution with red litmus paper. Observation: The red litmus paper turns blue.

• e) Sodium carbonate

  • Identification of cation (Na⁺): Test: Perform a flame test. Observation: A golden yellow flame is observed.
  • Identification of anion (CO₃²⁻): Test: Add dilute hydrochloric acid (HCl). Observation: Effervescence occurs, and the gas produced turns limewater milky.