Oxygen (O2) is necessary for cellular respiration; it must be transported from the lungs to tissues through the bloodstream. However, O2 is not very soluble in water. The Keq of oxygen dissolving at 310.0 K is 6.32 x 10-4. Calculate the AG(dissolve) for oxygen at 310.0 K, in kJ/mol.

A 30.0 mL aliquot of 0.300 M H_3 PO_4 is mixed with 90.0 mL of 0.200 M KOH, and the mixture is evaporated. Will the salt that crystallizes out be K_3 PO_4, K_2 HPO_4, or KH_2 PO_4? Show your calculations by using an ICE table (or two or three). H_3 PO_4(aq) + KOH_(aq) rightarrow KH_2 PO_4(aq) + H_2 O (l) The next proton on the H_2 PO_4^- would start to react only when more OH^- was added, over and above the first mole: KH_2 PO_4(aq) + KOH_(aq) rightarrow K_2 HPO_4(aq) + H_2 O (I) The final proton on the HPO_4^2- would start to react only when more OH^- was added, over and above the second mole: K_2 HPO_4(aq) + KOH_(aq) rightarrow K_3 PO_4(aq) + H_2 O (I)

1. Use the AG = AH – TAS relationship to justify why the solubility of KOH(s) in water decreases as temperature is increased. Do not do any calculations. (HINT: the S° value for KOH(s) is greater than that for KOH(aq).)

A solution was prepared by dissolving 0.687 g of sulfur, S, in 100.0 g of acetic acid, HC2H3O2. Calculate the freezing point and boiling point of the solution. (K, = 3.08°C/m and Kf = 3.59°C/m, T, = 118.5°C and T† = 16.60°C) Freezing point: °C Boiling point: °C