# pressure ..... chem question?

a sample of nitrogen gas was collected over water at 25 degree Celsius and a total pressure of 641 torr. the volume of gas collected is 500 ml. what is the volume of dry gas of STP???( at 25 degree Celsius the vapor pressure of water is 23.8 torr)

Relevance

_____PV = n RT

moles of gas are the same in both cases and R is a constant, so

(PV/T)stp = [(Ptotal-pH2O)V/T]exp

Vstp = [(Ptotal - pH2O)/Pstp] * (Tstp/Texp) = ??

Plug and SOLVE

Basic mathematics is a prerequisite to chemistry – I just try to help you with the methodology of solving the problem.