1. A sample was spotted on two different TLC plates:
a) One plate was placed in a chamber containing methanol, and after developed it showed one spot with an Rf value of 0.97. The other plate was placed in a chamber containing hexane, and after developed it showed two spots, one with an Rf value of 0.54 and one with an Rf value of 0.37. Explain how this occurred.
b) One plate was placed in a chamber containing hexane, and after developed it showed one spot with an Rf value of 0.05. The other plate was placed in a chamber containing ethyl acetate, and after developed it showed two spots, one with an Rf value of 0.15 and one with an Rf value of 0.46. Explain how this occurred.