Why does rapid distillation leads to poor separation of components?

Question

Why does rapid distillation leads to poor separation of components?

Answer 1

If distillation is caried out rapidly the result is too much turbulence in the distillation flask. This results in carry over of the distilling liquid and poor seperation of the components.

Answer 2

Because you don't reach the saturation point.

Answer 3

Trevor has certainly mentioned an important factor.  To me,  the most important factor is that, done right, distillation is an equilibrium process and in a multi-plate fractional distillation,  it takes time for the equilibrium to be established and continue to be maintained on each of the surfaces.   So if you distill too rapidly,  you will not establish the equilibrium on each of the surfaces but rather,  the vapor at the top of the equilibrium will be closer to the composition of the vapor right above the distillation flask and when it condenses,  it will be close to the composition in the flask.

To put it another way,  when you distill rapidly and don't establish the equilibrium on each of the surfaces,  you can reduce greatly the number of theoretical plates and reduce the separation capability of the distillation.