Chemical Analysis

• What is the test for hydrogen?

  Squeaky pop with a lit splint
• What is the test for carbon dioxide?

  Turns limewater cloudy
• What is the test for oxygen?

  Relights a glowing splint
• What is the test for chlorine?

  Bleaches damp litmus paper
• Cation


  positive ion
• Anion


  negative ion
• Ion


  charged particle
• Lithium flame test


  crimson red
• Sodium flame test

  yellow
• Potassium flame test

  lilac
• Copper flame test


  blue-green
• Calcium flame test


  brick red
• Aluminium and sodium hydroxide test

  white precipitate but dissolves with addition of excess sodium hydroxide
• Calcium and sodium hydroxide test


  White precipitate
• Magnesium and sodium hydroxide test

  White precipitate
• Iron (II) and sodium hydroxide test


  Green precipitate
• Iron (III) and sodium hydroxide test

  brown precipitate
• Copper (II) and sodium hydroxide test

  blue precipitate
• Yellow flame


  Sodium ion
• Lilac flame


  Potassium ion
• Crimson red flame


  Lithium ion
• Brick red flame


  Calcium ion
• Blue green flame


  Copper ion
• Green precipitate with sodium hydroxide

  Iron (II)
• Blue precipitate with sodium hydroxide


  Copper (II)
• Brown precipitate with sodium hydroxide


  Iron (III)
• White precipitate with sodium hydroxide

  Aluminium, calcium or magnesium ions
• White precipitate that dissolves in excess sodium hydroxide

  Aluminium ions
• Test for carbonates


  Add hydrochloric acid and effervescence occurs
• Carbonate test ionic equation

  2H⁺ ₊ CO₃²⁻ → H₂O ₊ CO₂
• Test for sulfates


  White precipitate with hydrochloric acid and barium chloride
• Ionic equation for sulfate test

  Ba²⁺ ₊ SO₄²⁻ → BaSO₄
• Test for chloride ions


  White precipitate with nitric acid and silver nitrate
• Test for bromide ions

  Cream precipitate with nitric acid and silver nitrate
• Test for iodide ions


  Yellow precipitate with nitric acid and silver nitrate
• Advantages of instrumental analysis

  Very sensitive

  Very fast

  Very accurate
• Disadvantages of instrumental analysis


  Expensive

  Training required
• How does flame emission spectroscopy work?

  metal solution placed in flame, light emitted passed through spectroscope which produces a line spectrum
• What happens to the electrons in flame emission spectroscopy?

  electrons gain energy and then release this energy as light
• What information does flame emission spectroscopy give?

  the metal ions in a mixture and their concentration