1. The problem statement, all variables and given/known data A chemical reaction is described by the equation N2O4 <> 2NO2. The pressure equilibrium constant for the given reaction is equal to 8 Pa. Which picture describes the equilibrium? (Please, see the attached file!). 2. Relevant equations N2O4 <> 2NO2 3. The attempt at a solution First I wrote the expression for the equilibrium constant of the given reaction. Kp = p^2(NO2) / p(N2O4). Then I tried to substitute partial pressures with the number of molecules for each type of the gass. It is not clear to me how can I use only number of molecules to replace partial pressures since I have the partial pressure squared in numerator. The pressure squared prevents for some things to be canceled in the expression for Kp if I apply Dalton's law for gas mixtures. Can somebody explain this to me, please.