Question

why is fractionating column packed with glass beds more efficient that a vigreux column of the same length and same diameter additionally why does the column need be wrapped with aluminum foil

Answer 1

Fractionating column is used for separation of liquid mixtures so its efficiency depends upon how easily it can separate liquid mixtures into liquid and vapour.

Fractionating column packed with glass beds more efficient than a vigreux column of the same length and same diameter because packing with glass beds provide more contact surface area in between liquid phase and vapour phase hence mass transfer can happen in an efficient way it causes the vapour to be more condensed on the plate that increases the efficiency of liquid separation.

But in the vigreux column there is no such packing which has less interior surface area than a column with packed ones and thus vigreux column is less efficient.

Hence fractionating column packed with glass beds more efficient than a vigreux column of the same length and same diameter.

To maintain a temperature equilibrium inside the column and to prevent the heat loss the column can be wrapped with aluminium foil. So that why the column is needed to wrapped with aluminium foil.