1. Compound two compounds, A and B, that can be separated by TLC using a certain solvent mixture. In that solvent, Rf=0.70 for B and Rf=0.65 for A. How far must the solvent front advance for there to be a 2.0-cm separation among the A and B spots on developed plate?
2. The same compounds A and B have different Rf values in a second solvent system: Rf=0.78 for B and Rf=0.81 for A. Which solvent system provides the greater separation?