# Boiling point of water and pressure relationship

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As elevation increases, atmospheric pressure and boiling point decrease. Evaporation of liquid in its entire volume is known as boiling. The boiling point is generally dependent on the ambient air pressure – the graph. The boiling point is the temperature at which the vapor pressure of the Even water will start boiling below degree C when we reduce the.

Read on to learn what exactly is the boiling point definition and what equation can you use to determine its value. Boiling point definition Boiling point is simply the temperature at which water starts boiling - in other words, it changes its state from liquid to gas. This temperature is dependent on pressure and the substance latent heat of vaporization.

Vapor Pressure and Boiling

The latter property is unique for each substance - you can be sure that two samples of water will have the same latent heat. Clausius—Clapeyron relation Our boiling point calculator uses the Clausius—Clapeyron relation to establish the boiling point of any substance at a given pressure. This equation characterizes phase transitions such as vaporization and relates the pressure to boiling point in a following way: It is also used by our ideal gas law calculator.

## How do atmospheric pressure and elevation affect boiling point?

How to calculate the boiling point Choose your substance. Is it water, or something different?

Note down its latent heat of vaporization. Perform an empirical experiment. We begin to pump the air out and we monitor the barometer display — See Video 1.

## Boiling point

In doing so we have to be careful not to expose the instrument to a very low pressure, which could damage it! Video 1 We now know that by pumping the air out of the vacuum container we take away the air and therefore the pressure decreases Second part: We boil water in the kettle.

After switching off the kettle we wait until the boiling stops and then pour the water into the vacuum container to a half of its height. We begin to pump and watch the behaviour of the water inside.

### thermodynamics - Relationship between boiling point and pressure - Physics Stack Exchange

Technical notes Vacuum containers are financially accessible and they can be easily obtained in kitchen utensil shops. This experiment requires a transparent container.

Before performing this experiment, it is necessary to determine the measuring range of the barometer in order to avoid any damage. During the experiment, it is necessary to follow the safety rules when working with hot water. Pedagogical notes For students it is not obvious whether during the pumping the pressure inside the container increases or decreases although the name vacuum container suggests it.

Therefore, it is appropriate to carry out both parts of the experiment, as described above; of course, if there is not an adequate barometer, we perform only the second part.

But be sure to comment it thoroughly.