The total pressure is 600 mmHg after 0.50 moles of nitrogen gas, #N_2#, and 1.0 mole of nitrogen dioxide, #NO_2#, gas are mixed in a closed container. There is no reaction between the gases. What is the partial pressure of the nitrogen dioxide?

1 Answer
Jun 27, 2017

#P_(NO_2)=400*mm*Hg#

Explanation:

Old #"Dalton's Law of partial pressures"# tells us that in a gaseous mixture, the partial pressure exerted by a component gas is the same as the pressure it would exert if it ALONE occupied the container.

The total pressure is the sum of the individual partial pressures.

Thus #P_"Total"=P_(NO_2)+P_(N_2)=600*mm*Hg#

But #P_(NO_2)=(1.0*molxxRT)/V#

And #P_(N_2)=(0.50*molxxRT)/V=1/2xxP_(NO_2)#

And so #P_"Total"=600*mm*Hg=3/2xxP_(NO_2)#

And finally, #P_(NO_2)=400*mm*Hg#, and #P_(N_2)=200*mm*Hg#; the which satisfies Dalton's Law....