What is the partial pressure of nitrogen?
Three of the primary components of air are carbon dioxide, nitrogen, and oxygen. In a sample containing a mixture of only these gases at exactly 1 atm the partial pressures of cardon dioxide & oxygen are given as PCO2=0.285torr and PO2=166.190torr
The total pressure of a mixture of gases is the sum of their partial pressures. In this case, we are given the total pressure as well as the partial pressure of two of the three components. Therefore we know that
P(total) = P(CO2) + P(O2) + P(N2)
Since the total pressure is in atmospheres and the partial pressures are in torr, we need to convert them to the same unit. We could convert the torr to atm but since we have two values already in torr, it's less work to convert atm to torr.
REmember that 1 atm = 760 torr, so the total pressure is 760 torr.
760 torr = P(CO2) + P(O2) + P(N2)
Now we can substitute in the values we know for CO2 and O2 to get
760 torr = 0.285 torr + 166.190 + P(N2)
Now we can solve for the pressure of N2 by subtracting to find
P(N2) = 593.525 torr