How to Calculate Water Boiling Temperature Pressure
Liquids come to a boil when their internal pressure equals the external pressure placed on them. The vapor pressure of a liquid is the movement within it as its molecules convert into a gaseous state. Higher temperatures speed up this conversion by increasing molecular activity, raising the internal pressure until the liquid reaches a boiling point, where it bubbles freely because the external pressure is no longer sufficient to keep it still. When external pressure is lower, for example at higher altitudes, water will boil at a lower temperature because it doesn't need as much internal pressure to counteract the external, atmospheric pressure. Does this Spark an idea?
Instructions
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1
Find the barometric pressure for the location where you will be boiling water. Barometric pressure depends on the altitude, but it also fluctuates with atmospheric conditions.
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2
Multiply the constant 49.161 by the natural logarithm multiplied by the barometric pressure expressed in inches Hg, which is a measure of the pressure that an inch of mercury exerts at 32 degrees Fahrenheit. You can calculate the natural logarithm on any calculator with advanced mathematical functions by using the "ln" button. If you don't have an advanced mathematical calculator, you can calculate a natural logarithm by visiting Wolframalpha.com.
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Add 44.932 to the number you reached in step 2 in order to calculate the temperature water will have to reach at your barometric pressure in order to boil.
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Alternately, you can consult a table that provides the boiling points of water at different atmospheric pressures, such as the one in the EngineeringToolbox.com link below.
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