Boiling point

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A boiling lake in Dominica

The boiling point of a substance is the temperature at which the substance boils, or enters a state of rapid evaporation. For water this is 100° Celsius or 212° Fahrenheit.

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

If you add sugar, salt or any other impurities to the water, it will usually make the boiling point higher. An exception is alcohol, which will have a lower boiling point.