A mixture of He , N2 , and Ar has a pressure of 22.7 atm at 28.0 °C. If the partial pressure of He is 1075 torr and that of Ar is 2605 mm Hg, what is the partial pressure of N2 ?

Answer 1

First, recognize that units of torr and mm Hg are the same. Also, 1 atm = 760 torr = 760 mm Hg

Sum of partial pressures of each gas will equal the total pressure.

Let's convert all pressure to atmospheres:

Total pressure = 22.7 atm

Partial pressure He = 1075 torr x 1 atm/760 torr = 1.414 atm

Partial pressure Ar = 2605 mm Hg x 1 atm/760 mm Hg = 3.428 atm

Partial pressure N₂ = ?

22.7 atm = 1.414 atm + 3.428 atm + x atm

x = 17.9 atm = partial pressure of N₂