1. The problem statement, all variables and given/known data I'm trying to figure out how to compute the average molecular weight of a gas mixture (nitrogen dioxide and dinitrogen tetroxide). I think I'm suppose to use this equation: M(mix)=X(NO2)M(NO2)+ X(N2O4)M(N2O4) , where I would just need to calculate the mole fractions and the molecular weight of the individual gases. Is this correct? If not assistance would be appreciated. Also I need to determine the equilibrium constant, delta G standard and delta S standard. I think to find the equilibrium constant I need to use this equation: K= n(N2O4)/((2)n(NO2)) ? To find delta G I could then use this equation: detla G= -RTlnK ? and I have no idea how to find delta S standard. Known: Pressure, Temp, Volume and three different weights of gas mixture. 2. Relevant equations M(mix)=X(NO2)M(NO2)+ X(N2O4)M(N2O4) K= n(N2O4)/((2)n(NO2)) detla G= -RTlnK 3. The attempt at a solution Ok I'm trying to get the mole fraction and ran into a little bit of a problem: nf= PV/RT= 0.95646 x105cm3x267.403 x10-6bar/ 8.31 x 303.15 K = 0.010153 mol ni+x=119.283g/(92 g/mol) = 1.29655 ? ni+x cannot equal nf when ni alone is larger. What am I doing wrong?