@X@user.full_name@X@ @GMU: How much time in days would it take for a 1.4017 g sample of 233Pa to decay to a mass of 0.9045 g if it has a half-life of 5.417e6 s.

@X@user.full_name@X@ @GMU: What is the standard free energy change for the following cell?2Cu+(aq) + Ni(s) → 2Cu(s) + Ni2+(aq) Ecoell = 0.780V

@X@user.full_name@X@ @GMU: What is the rate of consumption of C (M/s), if the rate of consumption of A is 0.231 M/s? Use the reaction below:2A + 3B + 4C → products

@X@user.full_name@X@ @GMU: NO2 at 383°C decomposes to form NO and O2 according to second order kinetics (see reaction below). The half-life for this reaction was measured to be 9.12e1 s when the initial concentration of NO2 was 2.28e-3 M. What is the rate constant for this reaction?2NO2(g) → 2NO(g) + O2(g)

@X@user.full_name@X@ @GMU: What is the standard free energy change for the following cell?3Ag+(aq) + Al(s) → 3Ag(s) + Al3+(aq) Ecoell = 2.459V

@X@user.full_name@X@ @GMU: What would the [OH-] be after addition of 11.35 mL of 0.1000 M NaOH to 25.00 mL of 0.1000 HA (a weak acid, Ka = 1.06e-5)?

@X@user.full_name@X@ @GMU: Which pair of substances are bases in the reaction below?H2PO-4 + HNO2 → H3PO4 + NO-2

@X@user.full_name@X@ @GMU: What is the solubility in g/L of H2S at a partial pressure of 500.9 torr, if the solubility at a partial pressure of 364.0 torr is 1.616 g/L?

@X@user.full_name@X@ @GMU: What is the value of Ksp in water, if 3.45e-4 M of A2B2 dissolves according to the reaction below?A2B2(s)→2A(aq) + 2B(aq) where A and B are ions

@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 0.1137. 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.