Steam distillation is used to purify a compound which is steam volatile and insoluble in…

Steam distillation is used to purify a compound which is steam volatile and insoluble in water. The impurities should not be steam volatile. It is based on the principle that liquid will boil when partial vapour pressure of liquid and partial vapour pressure of steam both become equal to atmospheric pressure, P = p₁ + p₂. It reduces the boiling point of a liquid.
\(\frac{\mathrm{Wt} \text {. of water distilled }}{\mathrm{Wt} \text { of substance distilled }}=\frac{\text { M.Wt. of water × VP of steam }}{\text { M.Wt. of substance × VP of aniline }}\) 
Isolation of essential oils from flowers, etc. is done by