Why is a fractionating column packed with small glass beads or tubing?

A fractionating column is packed with small glass beads or tubing to provide a large surface area for re-distillation. This design enhances the effectiveness of the separation process during fractional distillation.

In fractional distillation, the mixture of liquids is heated, and as components of the mixture vaporize, they ascend through the column. The packed materials create multiple surfaces for vapor to collide with during its upward journey. When vapor comes into contact with these surfaces, it cools and condenses, potentially leading to re-evaporation. This cycle of condensation and vaporization is critical in separating components based on their boiling points. The more opportunity there is for this interaction, the better the separation of different components, allowing for a more pure distillate to be obtained at the top of the column where the temperature is lower.

This increased surface area thus promotes efficient heat exchange and enhances the purification process, ultimately leading to improved separation of the components in the mixture.