On a thin layer chromatographic plate,an organic compound moved by $3.5 \ cm$,while the solvent moved by $5 \ cm$. The retardation factor of the organic compound is . . . . . . $\times 10^{-1}$.

The fragrance of flowers is due to the presence of some steam volatile organic compounds called essential oils. These are generally insoluble in water at room temperature but are miscible with water vapour in the vapour phase. $A$ suitable method for the extraction of these oils from the flowers is:

When the difference in boiling points of two liquids is very small,the separation is carried out by:

To separate different fractions of crude oil in the petroleum industry,the method used is:

When is distillation under reduced pressure used?

Steam distillation process cannot be used for purifying which of the following?