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[[File:Dominica boiling lake.jpg|thumb|A boiling lake in [[Dominica]]]]

[[File:Dominica boiling lake.jpg|thumb|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 pure [[water]] this is 100° [[Celsius]] or 212° [[Fahrenheit]], at [[Standard temperature and pressure|standard pressure]].  Standard pressure is 1.0 [[Atmosphere (unit)]]

The '''boiling point''' of a [[substance]] is the [[temperature]] at which the substance boils, or enters a state of rapid [[evaporation]].  For pure [[water]] this is 100° [[Celsius]] or 212° [[Fahrenheit]], at [[Standard temperature and pressure|standard pressure]].  Standard pressure is 1.0 [[Atmosphere (unit)]].

Boiling points can be changed in several ways. The addition of [[solute]]s or other substances usually changes the boiling point. Additionally, changing the [[pressure]] on a liquid changes its boiling point.  

Boiling points can be changed in several ways. The addition of [[solute]]s or other substances usually changes the boiling point. Additionally, changing the [[pressure]] on a liquid changes its boiling point.  

The boiling point of a liquid depends on the [[pressure]] of the surrounding air. An increase in air pressure raises the boiling point; a decrease in air pressure lowers 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). [[Aquanaut]]<nowiki/>s find that water in their habitat only boils at high pressure.

The boiling point of a liquid depends on the [[pressure]] of the surrounding air. An increase in air pressure raises the boiling point; a decrease in air pressure lowers 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). [[Aquanaut]]s find that water in their habitat only boils at high pressure.

Boiling point can also be defined in terms of [[vapour pressure]] as the temperature at which vapour pressure of liquid becomes equal to atmospheric pressure

Boiling point can also be defined in terms of [[vapour pressure]] as the temperature at which vapour pressure of liquid becomes equal to atmospheric pressure.

[[Sugar]], [[salt]] or other non-volatile [[solute]]<nowiki/>s in water will usually make the boiling point higher. [[Alcohol]], in contrast, is a volatile chemical that lowers the boiling point of water. Even a large amount dissolved in the water will usually make only small changes in the boiling point.

[[Sugar]], [[salt]] or other non-volatile [[solute]]s in water will usually make the boiling point higher. [[Alcohol]], in contrast, is a volatile chemical that lowers the boiling point of water. Even a large amount dissolved in the water will usually make only small changes in the boiling point.

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