If hydrogen gas is collected over water at 20 °C and 763 mm Hg,what is the partial pressure of the H₂? The vapor pressure of water at 20 °C is 17.5 mm Hg.

Question

Quizplus · Accepted Answer

The partial pressure of hydrogen gas in this case is equal to the total pressure minus the vapor pressure of water at that temperature. Therefore, the partial pressure of H₂ is:
763 mm Hg - 17.5 mm Hg = 746.5 mm Hg, which can be rounded to 746 mm Hg. Therefore, the correct answer is C) 746 mm Hg.

If Hydrogen Gas Is Collected Over Water at 20 °C