A-Level Chemistry PAG 4: Qualitative analysis of ions | Latest Version | Graded A+

A-Level Chemistry PAG 4: Qualitative analysis of ions | Latest Version | Graded A+ **What equipment is needed for the experiment?** The required equipment includes litmus paper, distilled water, a 25cm3 measuring cylinder, a 100cm3 beaker, a 100cm3 conical flask, dropping pipettes, a test-tube rack, 4 test tubes, a spatula, a glass rod, a Bunsen burner, 1 mol dm−3 nitric acid, 0.05 mol dm−3 silver nitrate, 0.2 mol dm−3 aqueous barium chloride, 0.4 mol dm−3 aqueous sodium hydroxide, and unknown solutions A, B, C, and D. **How can you identify solutions A, B, C, and D?** To identify the unknown solutions: 1. Add each solution to a separate test tube. 2. Add nitric acid to each test tube. Effervescence indicates the presence of carbonate ions, identifying the solution as sodium carbonate (Na2CO3). 3. Add barium nitrate to the remaining solutions. A white precipitate indicates sulfate ions, identifying the solution as sodium sulfate (Na2SO4). 4. Add silver nitrate to the last two solutions. Both should form white precipitates due to the presence of chloride ions. 5. Heat each remaining solution with sodium hydroxide and test the gas released with damp red litmus paper. If the paper turns blue, the solution contains ammonium ions, identifying it as ammonium chloride (NH4Cl). The other solution is sodium chloride (NaCl). **What are the full and ionic equations for the reaction of sodium chloride with silver nitrate?** Full equation: NaCl(aq) + AgNO3(aq) → AgCl(s) + NaNO3(aq) Ionic equation: Cl−(aq) + Ag+(aq) → AgCl(s) **What risk assessments should be conducted for solutions A-D, nitric acid, silver nitrate, barium chloride, and sodium hydroxide?** - **Solutions A-D:** Treat as irritants. Wear safety glasses, handle with care, and keep away from desk edges. - **Nitric acid (1.0 mol dm−3):** Irritant to eyes and skin. Wear safety glasses, handle with care, and keep away from desk edges. - **Silver nitrate (0.05 mol dm−3):** Causes staining. Wear gloves, safety glasses, and a lab coat. Keep away from surfaces. - **Barium chloride (0.2 mol dm−3):** Harmful if swallowed, irritates eyes, skin, and lungs. Wear safety glasses, avoid inhaling, and handle with care. - **Sodium hydroxide (0.4 mol dm−3):** Irritant. Wear safety glasses, handle with care, and keep away from desk edges. **What errors can occur during the experiment, and how can they be avoided?** Errors include unexpected insoluble