Q54PE - College Physics (Urone)

Question

At a spot in the high Andes, water boils at 80.0ºC, greatly reducing the cooking speed of potatoes, for example. What is atmospheric pressure at this location?

Step-by-Step Solution

Answer

The atmospheric pressure at the location at which water boils at \({\rm{80}}{\rm{.}}{{\rm{0}}^{\rm{o}}}{\rm{C}}\) is obtained as:\({\rm{4}}{\rm{.73 \times 1}}{{\rm{0}}^{\rm{4}}}{\rm{ Pa}}\).

Step1:Definition of boiling point

The boiling point of water is the temperature at which the water changes into a vapor state. The temperature at which the liquid's vapor pressure equals the atmospheric pressure of the surrounding environment is known as the boiling point.

Here, the boiling point is given as \({\rm{80}}{\rm{.}}{{\rm{0}}^{\rm{o}}}{\rm{C}}\). Water boils at this temperature. At high altitudes, atmospheric pressure is lower, so the boiling point is also lower than normal.

Step 2: Finding atmospheric pressure using the vapor pressure

As per the definition of the boiling point, the atmospheric pressure and vapour pressure will be equal at the boiling point. The vapour pressure corresponding to the boiling point of \({\rm{80}}{\rm{.}}{{\rm{0}}^{\rm{o}}}{\rm{C}}\)is \({\rm{4}}{\rm{.73 \times 1}}{{\rm{0}}^{\rm{4}}}{\rm{ Pa}}\). 

Since both are equal, atmospheric pressure is:\({\rm{4}}{\rm{.73 \times 1}}{{\rm{0}}^{\rm{4}}}{\rm{ Pa}}\).

Therefore, the atmospheric pressure at the location is:\({\rm{4}}{\rm{.73 \times 1}}{{\rm{0}}^{\rm{4}}}{\rm{ Pa}}\).