19. A mixture is spotted on a TLC plate. After developing, a single spot is obse
ID: 1024942 • Letter: 1
Question
19. A mixture is spotted on a TLC plate. After developing, a single spot is observed. This spot is almost at the solvent front. How can the separation be improved? a. use a smaller amount of sample b. use a larger amount of sample c. use a more polar solvent d. use a less polar solvent 20. In column chromatography using silica gel as the stationary phase, what would you do to shift the equilibrium from the solid stationary phase to the liquid mobile phase? a. use more polar mobile phase b. use less polar mobile phase c. increase the amount of mobile phase d. reduce the amount of stationary phaseExplanation / Answer
19. This is due to the compound is soluble in the solvent completely and moves along with the solvent front. This could be improved by lowering the solvent polarity. (d) Use a less polar solvent.
20. (a) Use more polar mobile phase.