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@X@user.full_name@X@ @GMU: Calculate the [H3O+] of 114.01 mL of a buffer initially consisting of 0.1752 M C2H5NH2 and 0.1926 M C2H5NH3Br after addition of 0.0031 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 2.7181 g sample of 137Cs to decay to a mass of 1.1715 g if it has a half-life of 9.461e8 s.

@X@user.full_name@X@ @GMU: What is the coefficient, b, in the reaction below, if Kc = 9.40e-6 and Kp = 0.0262 at 369.84°C?3A(s) + bB(g) → 4C(g)

@X@user.full_name@X@ @GMU: How much time in days would it take for a 2.6456 g sample of 3H to decay to a mass of 1.8024 g if it has a half-life of 3.879e8 s.

@X@user.full_name@X@ @GMU: When 10.52 g of aspirin was dissolved in 104.9 g of benzene, the freezing point was 275.7 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: Determine the molality of a 6.086 wt % aqueous solution of LiI.

@X@user.full_name@X@ @GMU: What is the correct expression for the solubility product of silver sulfate?Ag2SO4(s) → 2Ag+(aq) + SO42-(aq)

@X@user.full_name@X@ @GMU: The reaction below is an endothermic reaction. What would one have to do to shift the equilibrium to the right?SO2Cl2(g)→SO2(g) + Cl2(g)

@X@user.full_name@X@ @GMU: SrO has a face-centered cubic unit cell in which the O2- anions occupy corners and face centers, while the cations fit into the hole between adjacent anions. What is the radius of Sr2+ if the ionic radius of O2- is 140.0 pm and the density of SrO is 4.700 g/cm3?

John Schreifels @GMU: What is the total entropy change at 25oC for the reaction below, if the standard entropies of reactants and products are So (C(gr)) = 5.74 J/mol*K, So (H2(g)) = 130.68 J/mol*K, and So (C8H8(g)) = 345.2600 J/mol*K and the heat of formation of C8H8(g)) is 147.8500 kJ/mol.8C(gr) + 4H2(g) → C8H8(g)