SASS Chem P3 Tests for Unknown Anions

Sec 4 Chem Experiment 5.4: Tests for unknown Anions 1 St Andrew’s Secondary School Department of Science, Chemistry Name: ________________________( ) Class: _______ Date: __________ Aim: To conduct an anion test to deduce the anion present in solutions Solutions of Anion Tests Observations P To 2cm3 of the solution, add equal volume of silver nitrate solution and then dilute nitric acid. P To 2cm3 of the solution, add equal volume of dilute nitric acid and then barium nitrate solution Q To 2cm3 of the solution, add equal volume of silver nitrate solution and then dilute nitric acid. Q To 2cm3 of the solution, add dilute aqueous sodium hydroxide. Add 2 pieces of little aluminium foil. Warm the mixture gently and test the gas produced with a piece of damp/moist red litmus paper. R To 2cm3 of the solution, add equal volume of silver nitrate solution and then dilute nitric acid. S To 2cm3 of the solution, add equal volume of barium nitrate solution and then dilute nitric acid. T To 2cm3 of the solution, add 2cm3 of aqueous barium nitrate. Then add dilute nitric acid until no further changes are observed.

Sec 4 Chem Experiment 5.4: Tests for unknown Anions 2 St Andrew’s Secondary School Department of Science, Chemistry Conclusion: Deduce the anion present in each of the solution. Solution P: _____________________ Solution Q: _____________________ Solution R: _____________________ Solution S: _____________________ Solution T: _____________________ 1. In testing for the presence of chloride ions, acidified silver nitrate should be used. a. Silver nitrate is acidified by nitric acid. Explain why it shouldn’t be acidified using hydrochloric acid? ................................................................................................................................. ................................................................................................................................. ................................................................................................................................. b. What is the purpose for acidifying silver nitrate for the test of chloride ions? ................................................................................................................................. ................................................................................................................................. ................................................................................................................................. c. State the ionic equation for the test of chloride ions using aqueous silver nitrate. ................................................................................................................................. T To 2cm3 of the solution, add dilute hydrochloric acid. Pass the gas into limewater with the use of a delivery tube.