The standard molar free energies of formation of NO_2(g) and N_2O_4(g) at 25 deg
ID: 995159 • Letter: T
Question
The standard molar free energies of formation of NO_2(g) and N_2O_4(g) at 25 degree C are 51.840 and 98.061 kJ/mol, respectively What is the value of K_p(in aim) for the reaction written as follows at 25 degree C? 5.50 times 10^11 1.00 9.66 4.33 times 10^-36 7.91 times 10^-9 Polyethylene is a synthetic polymer or plastic with many uses. 1.41 g of a polyethylene sample was dissolved in enough benzene to make 100 mL of solution and the osmotic pressure was found to be 1.86 torr at 25 degree C. What is the approximate molar mass of the polyethylene? 185 g/mol 1.18 times 10^4 g/mol 7.29 times 10^5 g/mol 1.41 times 10^5 g/molExplanation / Answer
15.
G = Gprod - Greact = 98.061 - 51.84 = 46.221 kJ/mol = 46221 J/mol
G = -RT*ln(Kc)
46221 = -8.314*298*ln(kc)
Kc = exp(-46221 /(8.314*298)) = 7.90504*10^-9
Kp = Kc*(RT)^dn
dn =1-2 = -1
then
Kp = Kc*(RT)^-1
Kp = (7.90504*10^-9)*(0.082*298)^-1
Kp = 3.2349*10^-10