The method is used for mixtures having a low value of relative volatility, nearing unity.

The solvent interacts differently with the components of the mixture thereby causing their relative volatilities to change.

The solvent must alter the relative volatility by a wide enough margin for a successful result.

If the relative volatility is not constant from top to bottom of the column, then the following approximation may be used:

Greater deviations from Raoult's law make it easier to have significant changes in relative volatility with the addition of another component.

Vacuum distillation increases the relative volatility of the key components in many applications.

Lower pressures increase relative volatilities in most systems.

Trend trading is most effective for a market that is quiet (relative low volatility) and trending.

By convention, relative volatility is usually denoted as .

Large-scale industrial distillation is rarely undertaken if the relative volatility is less than 1.05.