Question

During last week’s lab of distillation, many of you had difficulties getting the fractional distillation column to work properly. Specifically, the liquid started condensing at the top of the fractional column and the vapor did not distill over. The lab instructor suggested that changing the bead size (which was in the column) to a larger size might improve the outcome of the experiment. Is this suggestion valid? Would it help the process or is this suggestion wrong? Explain your answer

Answer 1

The idea behind packing the fractionating column with glass beads (or something similar) is to provide the maximum possible surface area for the vapor to condense on.

The condensation of the vapor will decrease with decrease in surface area of the beads.

If the size of the beads is increased it will result in a decrease in the surface area of the beads( Recall that for a given mass, a material in the powder form will have a greater surface area than the same material in the bulk form) . This will result in a decrease in the condensation of the vapor inside the fractionating column and increase in the distilling over of the vapor.

So the suggestion by the instructor is valid and it would   help the process.