Question

Why does acetone speed up the rate at which fluorenone travels through alumina?

Answer 1

Here alumina is the stationary phase which is polar in nature.Fluorenone is also polar in nature.

Like likes like is the principle in chromatography. Polar stationary phase adheres polar compounds and hence they move slower in stationary phase.If we put in a polar solvent, that will compete with the alumina and also compete for space making the more polar elutents (compound ) travel quicker through.

Thus in this case polar fluorenone moves faster when acetone(polar) is introduced .