chromatography

• what is the use of chromatography?

  to separate out mixtures
• what is paper chromatography used for?

  separating out dyes; e.g. inks, paints, food colourings
• What is the first step in the process of paper chromatography?

  Draw a baseline using pencil
• Why is the baseline drawn near the bottom of the filter paper?

  To provide a starting point for ink spots
• What should be done after adding spots of different inks to the baseline?

  Loosely roll the sheet and put in solvent
• Why must the level of solvent be below the baseline?

  To prevent inks from dissolving into the solvent
• What is the purpose of placing a lid on the container during chromatography?

  To stop solvent from evaporating
• What happens to the solvent during the chromatography process?

  It seeps up the paper with inks
• How does each dye behave during the chromatography process?

  Each dye moves at different rates
• What is the result of the chromatography process called?

  A pattern of spots called chromatography
• When should the paper be taken out of the solvent during chromatography?

  When solvent is near the top
• What are the main steps in the process of paper chromatography?

  1. Draw a baseline using pencil.
  2. Add spots of different inks at intervals.
  3. Loosely roll the sheet and place in solvent.
  4. Ensure solvent level is below the baseline.
  5. Place lid on container to stop evaporation.
  6. Solvent seeps up paper with inks.
  7. Dyes move at different rates, forming spots.
  8. Remove paper when solvent is near the top.
  9. Result is a pattern of spots called chromatography.