Chemical analysis

• What is the ideal purity of a chemical compound?

  100% pure
• How is purity defined differently in chemistry compared to everyday language?

  In chemistry, purity refers to the absence of other substances, not just being in a natural state.
• What are the two phases in chromatography?

  • Mobile phase: where molecules can move
  • Stationary phase: where molecules are fixed
• What is chromatography used for?

  To separate and identify substances in a mixture.
• What are the tests for the four common gases?

  1. Chlorine: Bleaches damp litmus paper white.
  2. Oxygen: Relights a glowing splint.
  3. Carbon Dioxide: Turns limewater cloudy.
  4. Hydrogen: Produces a "squeaky pop" with a lit splint.
• What happens when chlorine gas is tested with damp litmus paper?

  It bleaches the paper, turning it white.
• What does oxygen do to a glowing splint?

  It relights the glowing splint.
• What is the result of bubbling carbon dioxide through limewater?

  It causes the solution to turn cloudy.
• What sound is produced when hydrogen is tested with a lit splint?

  A "squeaky pop" sound is produced.
• How can dilute acid help detect carbonates?

  • Dilute acid reacts with carbonates.
  • Produces carbon dioxide gas, which can be tested.
• What do flame tests identify?

  • Metal ions based on the color of the flame produced.
• What color flame do lithium ions produce?

  Crimson flame
• What color flame do sodium ions produce?

  Yellow flame
• What color flame do potassium ions produce?

  Lilac flame
• What color flame do calcium ions produce?

  Orange-red flame
• What color flame do copper ions produce?

  Green flame
• What is the process of flame emission spectroscopy?

  It identifies metal ions by analyzing the light emitted when they are heated.
• What happens to metal ions during flame emission spectroscopy?

  1. Metal ions are heated in a flame.
  2. Electrons become excited and emit light.
  3. Light passes through a prism to detect wavelengths.
  4. Each ion has a characteristic line spectrum.
  5. The intensity indicates ion concentration.
• How does flame emission spectroscopy work for mixtures?

  It can identify different ions in mixtures by analyzing their unique line spectra.
• What is the definition of purity in chemistry?

  Purity refers to the absence of other substances in a compound.
• What is the role of the stationary phase in chromatography?

  It is where the molecules are fixed and do not move.
• How do different ions produce different wavelengths of light in flame emission spectroscopy?

  Each ion has a unique charge and number of protons, leading to different electron transitions.