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John Schreifels @GMU: When 8.078 g of citric acid was dissolved in 104.5 g of benzene, the freezing point was 276.6 K. What is the formula mass of this compound? The freezing point depression constant for benzene is 5.12 (°C*kg)/mol. The melting point and boiling points are 5.50°C and 80.10°C, respectively.

@X@user.full_name@X@ @GMU: What is the temperature at which the reaction below becomes spontaneous, if the standard entropies of reactants and products at 25oC are So (C(gr)) = 5.74 J/mol*K, So(H2(g)) = 130.68 J/mol*K, and So (C3H6(g)) = 266.6000J/mol*K and the heat of formation of C3H6(g)) is 20.4200 kJ/mol?3C(gr) + 3H2(g) → C3H6(g)

@X@user.full_name@X@ @GMU: The reaction below occurs in the electrochemical cell. Which answer is correct?2Fe3+(aq) + 3Cd(s) → 2Fe(s) + 3Cd2+(aq)

@X@user.full_name@X@ @GMU: What would the pOH be after addition of 6.72 mL of 0.1000 M NaOH to 25.00 mL of 0.1000 HA (a weak acid, Ka = 5.51e-4)?

@X@user.full_name@X@ @GMU: What is the solubility in g/L of O2 at a partial pressure of 311.9 torr, if the solubility at a partial pressure of 518.4 torr is 0.03012 g/L?

John Schreifels @GMU: What is the change in mass of 95Mo when it is formed from protons, electrons and neutrons if the atom has a mass of 94.9058411 amu? The masses of the proton, electron and neutron are 1.00728 amu, 0.000549 amu and 1.00867 amu, respectively.

@X@user.full_name@X@ @GMU: Calculate the [H3O+] of 119.11 mL of a buffer initially consisting of 0.1104 M C2H5NH2 and 0.1023 M C2H5NH3NO3 after addition of 0.0021 mol of HCl. Assume that no volume change occurs after addition of the acid. The Kb of C2H5NH2 is 5.60e-4

@X@user.full_name@X@ @GMU: How much time in hours would it take for a 1.0229 g sample of 239Pu to decay to a mass of 0.7010 g if it has a half-life of 7.568e11 s.

@X@user.full_name@X@ @GMU: What is the rate of consumption of A (M/s), if the rate of consumption of B is 0.287 M/s? Use the reaction below:3A + 2B + 4C → products

@X@user.full_name@X@ @GMU: What is the standard free energy change for the ionization of HCN acid, if its Ka is 4.90e-10.