Section 3.12

The Effect of Air (Atmospheric / Barometric) Pressure on Boiling Point of Water

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Changes in Altitude Affect Boiling Point—The higher up you go the lower the Boiling Point –Why?

The higher altitude, the lower the atmospheric pressure….

As atmospheric pressure changes, so does the B.P. of water…. At a lower atmospheric pressure there is less

(air)pressure pushing down on the water, so the molecules can escape into the air easier, and thus, it takes less energy to boil water and the boiling point is lower.

As altitude increases, atmospheric pressure decreases and therefore, Boiling Point decreases!

•Burlington Illinois is about 930 feet above sea level. •What is the boiling point of water here?•210 º F or about 99 ºC