What happen when the paper is allowed to remain in the chamber after the solvent front reached the top layer?

Question

during paper chromatography, what disadvantages might occur if i let the paper remains in the chamber as the solvent front reached the top of the

layer???

Answer 1

Most of the time, the solvent reaches the top. Nothing seriously bad happens except if you left it very very long.

Answer 2

All your different fractions will bunch up like a traffic jam.and the top ones will start to dissolve properly and disappear.

Answer 3

Even if you don't leave it in long enough to get a "traffic jam" of spots at the top, you still can't calculate an Rf value since you don't know where the solvent front is.