Paper Chromatography

• Paper chromatography


  A separation technique used by scientists to separate substances in a mixture
• Paper chromatography is a physical process that does not involve chemical reactions and no new substances are made
• Stationary phase


  The paper, which does not move
• Mobile phase


  The solvent, which moves up the paper
• Solvents


  • There are lots of different solvents
• The solvent makes its way up the paper


  It dissolves the ink in the color dots and carries it up the paper
• A pure compound will produce a single spot in all solvents
• Compounds in a mixture may separate into different spots depending on the solvent
• Paper chromatography


  • Different substances have different solubilities
  • More soluble substances are more attracted to the mobile phase (solvent) and travel further than less soluble substances
• The starting line is drawn in pencil so the pencil does not dissolve in the solvent and move up the paper
• Rf value = Distance travelled by solute divided by the Distance travelled by solvent