6. A solution of Al2S3 is converted, by chemical means, to a form which can be precipitated as BaSO4. Calculate the gravimetric factor which allows determining BaSO4 from a sample of Al2S3.
7. What pH is required to just precipitate iron (III) hydroxide from a 0.10 M FeCl3 solution? Ksp for FE(OH)3 is 4 x 10^-38.
9. From the standard potentials of the following half-reactions, determine the reaction that will occur, and calculate the cell voltage from the reaction:
PtCl6 (2-) + 2e- = PtCl4 (2-) + 2Cl - E0 = 0.68 V
V3+ + e- = V2+ E0 = -0.255 V
This solution provides step-by-step calculations to determine gravimetric factor, pH levels and cell voltage in case-specific reactions.