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boiling point of water
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why does the boiling point of water decrease with a drop in pressure
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For more on marking an answer as the "Best Answer", please visit our FAQ.I agree with Gef.The reason for pressure cookers is to allow elevated temperatures through increasing the pressure, allowing the food to cook more quickly.
The link below gives a chart relating pressure and boiling point.
http://www.engineeringtoolbox.com/boiling-poin t-water-d_926.html
The link below gives a chart relating pressure and boiling point.
http://www.engineeringtoolbox.com/boiling-poin t-water-d_926.html
The lower the pressure the lower the boiling point. the boiling point of water drops 1oC for every 1000ft you go up. so the boiling point of water on top of Everest would be approx. 70 oC. Less pressure means less air molecules preventing the water molecules from escaping. so it boils at a lower temperature
PV=NRT
where p=pressure, v=volume, n=number of molecules, r=gas constant and t=temperature.
Boiling water is changing it from a liquid state to a gas state.
A gas has a greater volume than a liquid.
Therefore, by rearranging the formula above, you can see that in order to obtain a greater volume, with a lower pressure, you will need a lesser temperature increase.
Get it?
where p=pressure, v=volume, n=number of molecules, r=gas constant and t=temperature.
Boiling water is changing it from a liquid state to a gas state.
A gas has a greater volume than a liquid.
Therefore, by rearranging the formula above, you can see that in order to obtain a greater volume, with a lower pressure, you will need a lesser temperature increase.
Get it?