Question

A gas mixture contains each of the following gases at the indicated partial pressures: N2, 206 torr ; O2, 111 torr ; and He, 115 torr .

A.) What is the total pressure of the mixture?

B.) What mass of each gas is present in a 1.25 −L sample of this mixture at 25.0 ∘C?

      mN2, mO2, mHe =

Answer 1

PN2= 206 torr ; PO2= 111 torr ; and PHe =115 torr

total pressure = P_N2 + P_O2 + P_He

                       = 206 + 111+ 115 = .432tott

B. Pv =nRT

P_N2 = 206 torr = 206/760 = 0.271 atm

V = 1.25L

R = 0.0821l-atm/mole-K

T = 25C⁰ + 25 + 273 = 298K

M = 28

Pv =WRT/M

W = PVM/RT

   = 0.271*1.25*28/0.0821*298 = 0.387gm

Pv =WRT/M

W = PVM/RT

P_o2 = 111/760 = 0.146atm

W = PVM/RT

   = 0.146*1.25*32/0,0821*298

= 0.238gm

Pv =WRT/M

W = PVM/RT

P_He = 115/760 = 0.1513tm

W = PVM/RT

= 0.1513*1.25*4/0.08218298

= 0.0309gm