Practical 4

• Part 1 - The test for carbonate and sulfate ions in aqueous solution

  Ion: Carbonate ion, CO32-

  Reagent: Add dilute HCl and bubble the gas through limewater

  Observation: Fizzing and Limewater turns from colourless to cloudy

  Ion: Sulfate ion, SO42-

  Reagent: Add dilute HCl, then add barium chloride solution

  Observation: White precipitate
• Part 2 - Test for chloride, bromide and iodide ions in aqueous solution

  Add nitric acid HNO3 , then add silver nitrate AgNO3

  Chloride ion – white ppt

  Bromide ion – cream ppt

  Iodide ion – yellow ppt

  Dilute NH3

  Chloride ion - Dissolves

  Bromide ion - No observable change

  Iodide ion - No observable change

  Conc NH3

  Chloride ion - Dissolves

  Bromide ion - Dissolves

  Iodide ion - No observable change
• Part 3 - The test for halide ions in solid salts using concentrated sulfuric acid. Test for chloride in potassium chloride, bromide in potassium bromide and iodide in potassium iodide

  Ion and reagent : Potassium chloride + conc H2SO4

  Observation: Steamy fumes of HCl and Damp blue litmus paper turns red

  Ion and reagent : Potassium bromide + conc H2SO4

  Observation: Steamy fumes of HBr , Damp blue litmus paper turns red and Orange vapour of Br2
• Part 3 - The test for halide ions in solid salts using concentrated sulfuric acid. Test for chloride in potassium chloride, bromide in potassium bromide and iodide in potassium iodide

  Ion and reagent: Potassium iodide + conc H2SO4

  Observation: Steamy fumes of HI , Damp blue litmus paper turns red, Black solid of I2 , Purple vapour of I2 , Yellow solid of S and Bad smell of rotten eggs