@X@user.full_name@X@ @GMU: Which base listed below would be the best to creat a buffer having a pH of 8.2311?

@X@user.full_name@X@ @GMU: The vapor pressure of Ga (l) at 2546.1 K is 407.0 mm Hg. What is the heat of vaporization if its normal boiling point is 2676.2 K?

@X@user.full_name@X@ @GMU: What is the value of Ksp in water, if 1.91e-8 M of A2B3 dissolves according to the reaction below?A2B3(s)→2A(aq) + 3B(aq) where A and B are ions

@X@user.full_name@X@ @GMU: Initially there were equilibrium concentrations of 0.3554 M A, 0.2705 M B, and 0.1775 M C. Which change will cause the equilibrium to shift from left to right if the reaction is exothermic? Use the reaction below.6A(aq) → 2B(aq) +3C(aq) K = 0.547

@X@user.full_name@X@ @GMU: Uranium -238 decays in a series of steps to Pb-206. When the material is very old, one can treat the kinetics as a decay directly to Pb and the ratio of these two can be treated as a measure of the age of a rock. A rock containing 238U and 206Pb was examined to determine its approximate age. The molar ratio of 206Pb to 238U was 0.1308. Assuming no lead was originally present and that all lead formed remained in the rock, what is the age of the rock (in years)? The half-life of 238U is 4.50e9 yr.

@X@user.full_name@X@ @GMU: What is the solubility in g/L of CO at a partial pressure of 288.7 torr, if the solubility at a partial pressure of 426.9 torr is 0.01636 g/L?

@X@user.full_name@X@ @GMU: What would the pOH be after addition of 13.81 mL of 0.1000 M NaOH to 25.00 mL of 0.1000 HA (a weak acid, Ka = 3.01e-4)?

@X@user.full_name@X@ @GMU: What is the solubility in mol/L of Kr at a partial pressure of 623.6 torr, if the solubility at a partial pressure of 463.7 torr is 0.001702 mol/L?

@X@user.full_name@X@ @GMU: Uranium -238 decays in a series of steps to Pb-206. When the material is very old, one can treat the kinetics as a decay directly to Pb and the ratio of these two can be treated as a measure of the age of a rock. A rock containing 238U and 206Pb was examined to determine its approximate age. The molar ratio of 206Pb to 238U was 0.2165. Assuming no lead was originally present and that all lead formed remained in the rock, what is the age of the rock (in years)? The half-life of 238U is 4.50e9 yr.

@X@user.full_name@X@ @GMU: What is the pH of 1.58e-4 M H2SO4 ?