Question

The boiling temperature of water is 373K at 1 atm. What is the boiling temperature of water at higher altitude (say 0.3atm, ~30 kPa, the pressure at the top of Mount Everest), given that dH(vap) = 40.66 kJ/mol?

a) 353K

b) 363K

c) 373K

d) 383K

Answer 1

Boiling points are affected by external pressure. As altitude increases, the atmospheric pressure decreases, causing the boiling temperature of water to decrease. The boiling temperature of water at 0.3 atm pressure is lower than at 1 atm.

Step-by-step explanation:

Boiling points of liquids are affected by external pressure. At higher altitudes, such as the top of Mount Everest, the atmospheric pressure is lower than at sea level. With lower pressure pushing down on the liquid surface, water boils at a lower temperature. The boiling temperature of water at 0.3 atm (30 kPa) would be lower than the boiling temperature at 1 atm. The enthalpy of vaporization (dH(vap)) value is not directly needed to determine the boiling temperature at different pressures.

Therefore, the boiling temperature of water at higher altitudes (0.3 atm) would be lower than the boiling temperature at 1 atm. Based on the given options, the correct answer in this case would be a) 353K.