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Hiranandani Foundation School, Thane STD X Practical Chemistry Types of expected questions: Identify the cation / anion in the given unknown salt. Identify the given salt. Name the chemical reagent that will be used to differentiate between the following salts. Write a chemical test to distinguish between the given salts or compounds. State your observation when the given reagents are added to the following salts. IDENTIFICATION OF ANIONS Salt A Salt B Reagent used Dil H 2 SO4 Observation A Observation B 1. Carbonate Sulphite Brisk effervescence of a colourless gas which has no effect on K 2 Cr2 O7 A gas with a suffocating odour which turns K 2 Cr2 O7 solution from orange to green White precipitate soluble in dil HCl / HN O3 A gas with a suffocating odour which turns K 2 Cr2 O7 solution from orange to green A gas with a rotten egg smell, which turns lead acetate paper silvery black 2. Sulphate Sulphide Dil H 2 SO4 3. Carbonate Sulphate Barium chloride 4. Chloride Nitrate Silver nitrate soln. Dil H 2 SO4 White precipitate soluble in N H 4 OH No reaction seen. 5. Carbonate Sulphide Brisk effervescence of a colourless gas which has no effect on K 2 Cr2 O7 A gas with a rotten egg smell, which turns lead acetate paper silvery black 6. Sulphate Nitrate Barium Nitrate soln. White precipitate insoluble in dil HCl No reaction seen. White precipitate insoluble in dil HCl / HN O3 IDENTIFICATION OF CATIONS Salt A Salt B Observation A Observation B Lead Reagent used NaOH 1. Ferrous Dirty green ppt insoluble in excess Chalky white ppt soluble in excess 2. Ferrous Ferric NaOH Dirty green ppt insoluble in excess Reddish brown ppt insoluble in excess 3. Copper Calcium NaOH Pale blue ppt insoluble in excess Milky white ppt insoluble in excess 4. Calcium Lead N H 4 OH No ppt Chalky white ppt insoluble in excess. 5. Calcium Zinc N H 4 OH No ppt Gelatinous white ppt soluble in excess 6. Zinc Lead N H 4 OH Gelatinous white ppt soluble in excess Chalky white ppt insoluble in excess TO DISTINGUISH BETWEEN CERTAIN COMPOUNDS Compound A Copper(II) Oxide Compound B Reagent used Observation A Observation B Manganese Dioxide Conc HCl Chlorine gas not evolved Greenish yellow chlorine gas which turns starch iodide paper bluish black. 2. Hydrochloric acid Sodium Hydroxide Sodium carbonate solution No gas evolved 3. Sulphuric acid Sodium hydroxide Ammonium chloride solution Brisk effervescence of a colourless gas which turns lime water milky No visible reaction 1. An alkaline gas is formed which turns Nessler's reagent brown.
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