1. The problem statement, all variables and given/known data A monatomic ideal gas initially has a volume of 3 m^3, a temperature of 300 K and is at a pressure of 1x 10^5 Pa. It is compressed adiabatically and quasi-statically to a volume of 2 m^3. Calculate its final pressure and temperature. 2. Relevant equations Po(Vo ^gamma)= P1(V1^gamma) PV= NKbT 3. The attempt at a solution degrees of freedom (nd)= 3 gamma = nd+2/ nd = 5/3 Vo = 3m^3 ; V1= 2m^3 P0 = 1x10^5Pa ; P1 = ? The new pressure ; P1 = 1.97 x 10^5 Pa Re-arrange to get T= P1V1 / N Kb N = V0 / 22.47 x 6.02 x10^23 (avogadro's number) = 8.036 x10 ^25 So T = 355.23K I understand the method, but I do not understand where the value of 22.47 comes from. But i think that V0/22.47 is to find the number of moles. Help please?