The mole fraction of nitrogen in dry air near sea level is 0.78084, where the molar mass of nitrogen is 28.013. The partial pressure of nitrogen when the total atmospheric pressure (dry air)is 97.5 kPa is ________ kPa.

Question

Quizplus · Accepted Answer

According to Dalton's Law of Partial Pressure, the partial pressure of each gas in a mixture of gases is equal to the total pressure multiplied by the mole fraction of that gas. Therefore, the partial pressure of nitrogen can be calculated as:

partial pressure of nitrogen = mole fraction of nitrogen x total atmospheric pressure
partial pressure of nitrogen = 0.78084 x 97.5 kPa
partial pressure of nitrogen = 76.12 kPa

Therefore, the best choice is C, 77.0 kPa, which is the closest value to the calculated partial pressure of nitrogen.

The Mole Fraction of Nitrogen in Dry Air near Sea