topic 8

• Lithium flame test

  • crimson flame
• sodium flame test

  • yellow flame
• potassium flame test

  • lilac flame
• calcium flame test

  • orange/red flame
• copper (II) flame test

  • green flame
• Carbonate ions

  • bubbles produced and limewater goes cloudy
• sulphate ions

  • white precipitate formed if present
• Halide ions

  • chloride - white precipitate
  • bromide - cream precipitate
  • Iodide - yellow precipitate
• Oxygen test

  • lit splint will reignite if oxygen is present
• hydrogen test

  • lit splint in a test tube containing gas
  • if hydrogen is present there will be a squeaky pop sound
• chlorine test

  • damp blue litmus paper will be bleached red then white
• carbon dioxide test

  • limewater turns milky
• Advantage of using flame emission spectroscopy

  • more accurate
  • more sensitive
  • faster
• What does flame emission spectroscopy produce when metal ions are heated?

  Characteristic line spectrum
• What happens to metal ions when heated in flame emission spectroscopy?

  They lose electrons and emit light
• What does the light emitted by metal ions depend on?

  Its color and combination of wavelengths
• How does the uniqueness of a spectrum help in flame emission spectroscopy?

  It indicates the unique identity of an ion
• How can the intensity of a spectrum be used in analysis?

  To identify the amount of substances
• What can line spectra be used for in solutions?

  Identify ions and calculate their concentration
• What is a key advantage of flame emission spectroscopy for mixtures?

  It can identify different ions in mixtures
• How can a spectrum for a mixture be analyzed?

  By comparing it against reference spectra
• What is one advantage of using machines for chemical analysis?

  They are very sensitive to substances
• Why are machines like flame emission spectroscopy preferred in analysis?

  They are fast, accurate, and can be automated
• What are the tests for the four common gases?

  1. Chlorine: Turns damp blue litmus paper white
  2. Oxygen: Relights a glowing splint
  3. Carbon Dioxide: Turns limewater cloudy
  4. Hydrogen: Produces a 'squeaky pop' sound
• How can carbonates be detected in a solution?

  By adding dilute acid and observing bubbles
• What happens when carbonates react with dilute acid?

  Carbon dioxide is released, turning limewater cloudy
• How can sulfate ions be identified?

  By adding HCl and barium chloride to form a precipitate
• What precipitate forms when sulfate ions are present?

  White precipitate of barium sulfate
• How can halide ions be identified?

  By adding nitric acid and silver nitrate
• What precipitate forms with chloride ions?

  White precipitate of silver chloride
• What color precipitate forms with bromide ions?

  Cream precipitate of silver bromide
• What color precipitate forms with iodide ions?

  Yellow precipitate of silver iodide
• What is the purpose of a flame test for metal ions?

  To identify the metal ion by flame color
• What color flame does lithium produce?

  Crimson flame
• What color flame does sodium produce?

  Yellow flame
• What color flame does potassium produce?

  Lilac flame
• What color flame does calcium produce?

  Orange-red flame
• What color flame does copper produce?

  Green flame
• What is the procedure for conducting a flame test?

  Clean wire, dip in sample, heat, observe color
• What happens when sodium hydroxide is added to a metal solution?

  • Coloured precipitate may form
  • Indicates presence of specific metal ions