if a perfect separation of two components A and B is achieved during a distillation, a plot of temperature vs volume of condensate looks like the ideal graph(figure1) the entire lower boiling component A distills at its boiling point until it is removed from the mixture; then, the higher boiling component B distills at its boiling point ideal separations are not achieved when separating mixtures of compounds with boiling points closer together than 10 this is because the component B has an appreciable vapor pressure at the boiling point of component A in a laboratory situation one can plot the volume of distillate vs temperature of the distilling vapor to determine how closely a distillation resemble an ideal separation