Question

What is boiling point of water at (i) higher altitudes, (ii) in pressure cooker ?

Answer 1

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(i) When atmospheric pressure is lower, such as at a higher altitude, it takes less energy to bring water to the boiling point. Less energy means less heat, which means water will boil at a lower temperature at a higher altitude.


(ii) 121 °C In a sealed pressure cooker, the boiling point of water increases as the pressure rises, resulting in superheated water. At a pressure of 1 bar or ~15 psi (pounds per square inch) above the existing atmospheric pressure, water in a pressure cooker can reach a temperature of up to 121 °C (250 °F), depending on altitude.


Hope its help you

Answer 2

1. At higher altitudes the densities of the gases decreases, so it is difficult for us to breathe. If the density of the gases decreases so the atmospheric pressure also decreases at higher altitudes. When vapour pressure is equal to atmospheric pressure the liquid starts boils. Lower the atmospheric pressure lower will be the boiling point. So the water boils below 100 degree at higher altitudes.

2. In the sealed pressure the boiling point of the water increases as the pressure increases to result a super heat liquid. The temperature of water in the pressure cooker is about 120˚C.