One can change the boiling point of liquids by adding an "inhibitor." The change in boiling point can be found about right from:
where ΔTB.P. = change in boiling point, Kb = a constant (this is .56 for water), and m = molality of the solute.
The boiling point of a liquid also depends on the pressure of the surrounding air. An increase in air pressure increases the boiling point; a decrease decreases the boiling point. In the low pressure environment at the top of Mt Everest for example, water boils at only 69 °C. (156.2 °F). It can also be defined in terms of vapour pressure as the temperature at which vapour pressure of liquid becomes equal to atmospheric pressure