Anion Tests

• To test for the presence of Chloride, add dilute nitric acid to the solution, then add silver nitrate to the solution. If chloride is present, white precipitate is formed.
• To test for the presence of Iodide, add dilute nitric acid to the solution, then add silver nitrate to the solution. If Iodide is present, yellow precipitate is formed.
• To test for the presence of Nitrate, add aqueous sodium hydroxide to the solution. Then, add a piece of aluminium foil to the solution and warm it. Then, place a piece of damp red litmus paper near the test tube and if the paper turns blue, nitrate is present in the solution. The gas evolved is ammonium.
• To test for the presence of Carbonate, add dilute acid to the solution and pass on the gas produced into limewater. If carbonate is present, white precipitate is then formed in the limewater and effervescence is observed. The gas produced would be Carbon Dioxide.
• The test for sulfate anions is to add dilute nitric acid, then add barium nitrate to the solution and if white precipitate forms, sulfate is present.