Chemical Analysis (C8)

• What is one way to determine if a substance is pure?

  Testing its melting or boiling point
• What is a formulation in chemistry?

  A mixture designed for a specific purpose
• What is the stationary phase in chromatography?

  Chromatography paper or filter paper
• What is the purpose of the mobile phase in chromatography?

  To help substances move up the stationary phase
• What is the RF value in chromatography?

  The ratio of how far a spot moved compared to the solvent
• How can you test for hydrogen gas?

  Hold a burning splint over the test tube
• What color flame does lithium produce in a flame test?

  Crimson
• What happens when sodium hydroxide is added to a solution containing aluminium ions?

  A white precipitate forms, then dissolves with excess NaOH
• What is the color of the precipitate formed when silver nitrate is added to a solution containing chloride ions?

  White
• How can you test for sulfate ions in a solution?

  Add barium chloride and hydrochloric acid
• Why are instrumental methods like flame emission spectroscopy preferred in professional labs?

  They are accurate, sensitive, and fast
• What is the color of the flame produced by potassium in a flame test?

  Lilac
• What is the purpose of drawing a line in pencil at the bottom of the chromatography paper?

  To mark the starting point for the solvent and substances
• What is the RF value if a substance moves 3 cm and the solvent moves 6 cm?

  $0.5$
• What is the color of the flame produced by calcium in a flame test?

  Orange-red
• What happens when carbon dioxide is bubbled through lime water?

  It turns cloudy
• What is the color of the precipitate formed when silver nitrate is added to a solution containing bromide ions?

  Cream
• What is the color of the flame produced by copper in a flame test?

  Green
• What is the purpose of using a spectroscope in flame emission spectroscopy?

  To identify the wavelengths of light emitted
• What is the RF value if a substance moves 4 cm and the solvent moves 8 cm?

  $0.5$
• What is the color of the flame produced by sodium in a flame test?

  Yellow
• What happens when chlorine gas is tested with damp blue litmus paper?

  It turns white
• What is the color of the precipitate formed when silver nitrate is added to a solution containing iodide ions?

  Yellow
• What is the color of the flame produced by magnesium in a flame test?

  No specific color (not mentioned in the text)
• What is the purpose of adding nitric acid in the test for halide ions?

  To ensure the formation of the correct precipitate
• What is the RF value if a substance moves 2 cm and the solvent moves 10 cm?

  $0.2$
• What is the color of the flame produced by iron(III) ions in a flame test?

  Brown
• What is the purpose of using hydrochloric acid in the test for sulfate ions?

  To ensure the formation of the correct precipitate
• What is the color of the precipitate formed when sodium hydroxide is added to a solution containing copper(II) ions?

  Blue
• What is the color of the flame produced by iron(II) ions in a flame test?

  Green
• What is the purpose of using barium chloride in the test for sulfate ions?

  To form a white precipitate with sulfate ions
• What is the color of the precipitate formed when sodium hydroxide is added to a solution containing iron(III) ions?

  Brown
• What is the color of the flame produced by copper in a flame test?

  Green
• What is the purpose of using a spectroscope in flame emission spectroscopy?

  To identify the wavelengths of light emitted
• What is the RF value if a substance moves 5 cm and the solvent moves 10 cm?

  $0.5$
• What is the color of the flame produced by sodium in a flame test?

  Yellow
• What happens when chlorine gas is tested with damp blue litmus paper?

  It turns white
• What is the color of the precipitate formed when silver nitrate is added to a solution containing iodide ions?

  Yellow
• What is the color of the flame produced by magnesium in a flame test?

  No specific color (not mentioned in the text)
• What is the purpose of adding nitric acid in the test for halide ions?

  To ensure the formation of the correct precipitate