1. The problem statement, all variables and given/known data Given are two relations for the molar volume. Are they possible? If so, give the formula for v in function of P and T. a) dv =R/P dT - RT/P² dP b) dv = 2R/P dT - RT/2P² dP 2. Relevant equations 3. The attempt at a solution If I integrate dv I get ∫R/P dT - ∫RT/P² dP= RT/P + RT/P (in case a) and 5/4 * RT/P (in case b). does this mean they are both 'possible'? intuitively I would say only a is possible another thing that struck me - probably resulting from some kind of error I made- was the following discrepancy: say v=RT/P then dv=dv/dT dT + dv/dP dP = R/P dT - RT/P² dP. So according to this v=RT/P might well be the solution to the integral ∫dv (in the case of a).