Define ascending type of paper chromatography?
The ascending type consists in dipping the lower end of the paper containing the sample spots into the solvent so that it is above the solvent depth and then allowing it to rise up the paper by capillary action. The mobile phase or solvent moves in the upward direction against the gravitational force. The rate of movement of solvent becomes slower with increasing height which provides enough time for partition equilibrium between the two phases to take place. However the disadvantage in this is that compounds with low Rf values may not separate well.