Dry air is 78.08% nitrogen, 20.95% oxygen and 0.93% argon with the 0.04% being other gases. if the atmospheric pressure is 760.0 torr, what is the partial pressure of nitrogen in dry air?

Partial pressure (N2) = mole fraction * total pressure

{ 1 mole of any ideal gas occupy same volume of 1 mole of any other ideal gas under same condition of temperature and pressure so mole fraction in the sample is simply 78.08% = 0.7808 this is because equal volume of each gas has equal moles

partial pressure N2 = 0.7808 * 760.0

partial pressure = 593.4 mmhg (1 torr = 1mmhg)