Chromatography

• What is required for practical chromatography?

  Combined required practical chromatography
• How should you draw a horizontal pencil line on chromatography paper?

  Use a ruler to draw a horizontal line
• How far should lines be from the edge of chromatography paper?

  Lines should be around 2 cm from the edge
• What should you mark on the chromatography paper?

  Mark five pencil spots at equal spaces
• What should be left clear at each side of the chromatography paper?

  Leave 1 cm clear at each side
• What tool is used to put small spots of food color on chromatography paper?

  Use a capillary tube to put spots
• What should be poured into a beaker for chromatography?

  Pour water into a beaker to a depth of 1 cm
• How should the chromatography paper be attached to the beaker?

  Attach the paper using tape to the beaker
• Where should the pencil line be in relation to the water level?

  The pencil line must be above the water level
• What is added to reduce evaporation of the solvent in chromatography?

  Put a lid on the beaker to reduce evaporation
• What happens to the water during chromatography?

  The water will move up the paper
• When should the chromatography paper be removed from the beaker?

  Remove the paper when water travels 3/4 up
• What should be used to mark where the water reached on the chromatography paper?

  Use a pencil to mark the water reach
• What should be done with the paper after the experiment?

  Hang the paper to dry after the experiment
• What are the steps to calculate the RF value in chromatography?

  1. Measure the distance from the pencil line to the center of each spot.
  2. Measure the distance moved by the solvent front.
  3. Divide the distance moved by the spot by the distance moved by the solvent front.
• What is the first step in calculating the RF value?

  Measure the distance from the pencil line
• What does the RF value represent in chromatography?

  The RF value represents the distance traveled by the spot
• How do you find the distance moved by the solvent front?

  Measure the distance from the pencil line to the solvent front
• If the distance moved by the spot is $2 \text{ cm}$ and the solvent front is $5 \text{ cm}$, what is the RF value?


  $0.4$
• What is the formula for calculating RF value?

  RF = distance moved by spot / distance moved by solvent