Molecules in a mixture are separated based on their relative attraction to the mobile phase (running solvent) vs the stationary phase (chromatography paper)
Extracting photosynthetic pigments
Use a pestle & mortar to grind a leaf with an extraction solvent
Paper chromatography to separate photosynthetic pigments
1. Use a capillary tube to spot pigment extract onto the pencil 'start line' (origin) 1 cm above bottom of paper
2. Place chromatography paper in solvent (origin should be above solvent level)
3. Allow solvent to run until it almost touches the other end of the paper. Pigments move different distances
Rf values- Ratios that allow comparison of how far molecules have moved in chromatograms
Rf value = distance between origin & centre of pigment spot / distance between origin & solventfront.
Advantage of having different colored pigments in leaves
Different/more wavelengths (of light) for photosynthesis
