Qualtive analysis 1.2.1

• What is the purpose of qualitative analysis of ions in chemistry?

  To identify positive ions in samples
• What are the steps for testing positive ions in a sample?

  • Dissolve solid in deionised water
  • Add barium chloride and sodium hydroxide
  • Swirl to mix and add NaOH until in excess
  • Repeat for calcium, magnesium, and strontium
  • Note observations in a results table
• What ions are specifically tested for in qualitative analysis?

  Group 2 ions and ammonium ions
• How should a solid sample be prepared for testing positive ions?

  It must be dissolved in deionised water
• What is the first step in testing for Group 2 metal ions?

  Add barium chloride solution to a test tube
• What should be done after adding sodium hydroxide to the test tube?

  Swirl the test tube to mix well
• What is the significance of adding sodium hydroxide dropwise?

  To ensure the solution does not exceed the limit
• What should be noted down during the testing process?

  Any observations in a results table
• How can ammonium ions be tested in a solution?

  Add sodium hydroxide and heat the mixture
• What is the purpose of holding damp red litmus paper near the test tube?

  To detect the presence of ammonia fumes
• What happens when the solution containing ammonium ions is heated?

  Fumes are produced that indicate ammonia
• What is the role of the Bunsen burner in the ammonium ion test?

  To provide gentle heat for the reaction
• How does the qualitative analysis of ions contribute to chemistry?

  It helps identify unknown substances in samples
• What solutions should be tested for Group 2 ions?

  Calcium chloride, magnesium chloride, strontium chloride
• What should be done with observations during the tests?

  They should be noted in a results table
• Which solutions can also be tested similarly to Group 2 ions?

  Ammonia solution and sulfuric acid solution
• How many drops of ammonium chloride should be added for testing?

  About 10 drops
• What should be added to the test tube after ammonium chloride?

  About 10 drops of sodium hydroxide
• What is the purpose of swirling the test tube after adding sodium hydroxide?

  To ensure the solution is mixed well
• How should the test tube be heated during the ammonium ion test?

  In a water bath above a Bunsen burner
• What indicates the presence of ammonia gas during the test?

  Damp red litmus paper turns blue
• What ions can be identified through simple test tube reactions?

  Halide, hydroxide, carbonate, sulfate ions
• What must be done if the sample to be tested is solid?

  Dissolve it in deionised water
• What should be added to the test tube when testing for halide ions?

  Nitric acid and silver nitrate solution
• What happens if a halide ion is present in the sample?

  A precipitate will form (white, cream, yellow)
• What is the white precipitate formed when chloride ions are present?

  AgCl
• What precipitate forms if bromide ions are present?

  AgBr
• What precipitate is formed when iodide ions are present?

  AgI
• What is the purpose of using ammonia solution in halide testing?

  To further distinguish between silver halide precipitates
• How should hydroxide ions be tested?

  Test the pH with litmus or universal indicator
• What indicates the presence of hydroxide ions in a solution?

  Red litmus paper turns blue
• How can carbonate ions be tested?

  Add dilute hydrochloric acid and sodium carbonate
• What gas is produced when carbonate ions react with acid?

  Carbon dioxide gas
• What happens to limewater when carbon dioxide is bubbled through it?

  It turns milky
• What is the test for sulfate ions?

  Add dilute hydrochloric acid and barium chloride
• What precipitate indicates the presence of sulfate ions?

  White precipitate of barium sulfate
• Why is hydrochloric acid added before testing for sulfate ions?

  To remove any carbonates that may interfere
• What is the procedure for testing Group 2 ions?

  Test with calcium, magnesium, strontium chloride solutions
• Why is it important to note observations in a results table?

  To organize and analyze the results effectively
• How do you test for ammonium ions?

  Add ammonium chloride and sodium hydroxide