chemical analysis

Cards (14)

  • a pure substance contains only one type of element or compound.
  • pure substances
    • melt and solidify at one fixed temperature.
    • boil and condense at one temperature
  • impure substances change state at a range of temperatures.
  • formulations are mixtures designed to have specific properties.
  • examples of formulations:
    • fuels
    • cleaning agents
    • paints
    • medicines
    • fertilizers
  • chromatography involves:
    • a stationary phase
    • a mobile phase (moving)
  • in paper chromatography:
    • the stationary phase is the absorbent paper.
    • the mobile phase is the solvent, often water.
  • during chromatography
    • mixtures are separated into their components.
    • the solvent dissolves the samples and carries them up the water.
    • each component moves a different distance up the paper, depending on the attraction to the paper and solvent.
  • chromatography:
    1. draw a start line in pencil
    2. put samples of food coloring
    3. unknown substance (x)
    4. dip the paper in the solvent
    5. wait
    6. identify the unknown substance.
  • hydrogen test: squeaky pop.
  • hydrogen test:
    1. hold a lit splint over a tube with the gas in
    2. if its hydrogen it will make a squeaky pop.
  • chlorine test:
    1. dunk litmus paper in substance
    2. if chlorine litmus paper will turn white.
  • oxygen:
    1. hold a glowing splint over a test tube of gas.
    2. if oxygen the splint will relight.
  • carbon dioxide:
    1. bubble through limewater
    2. if carbon dioxide, limewater will turn cloudy.