Question

During a column chromatography laboratory experiment, a column is to be run with hexane first, then a hexane/ dichloromethane mixture, then 100% dichloromethane. What will happen if you mix up the hexane and dichloromethane? How can you fix the problem?

Answer 1

Hexane is 'non-polar' solvent; and dichloromethane is 'polar' solvent.

If we mixed up the hexane with gradual increasing amounts of dichloromethane, the resulting mixture polarity increased.

Here, both hexane and dichloromethane are miscible.

If we run the column with hexane, the non-polar components which are present in the reaction mixture will eluted first. Upon gradual increasing the concentration of dichloromethane, moderately polar components eluted. When we take 100% dichloromethane, the remaining more polar compound will eluted.