Part -1:

Question:

1. Write the ionic equation for dissolution and the solubility product (Ksp) expression for each of the following slightly soluble ionic compounds:

(a) PbCl₂
(b) Ag₂S
(c) Sr₃(PO₄)₂
(d) SrSO₄

2. Assuming that no equilibria other than dissolution are involved, calculate the molar solubility of each of the following from its solubility product:
(a) Ag₂SO₄
(b) PbBr₂
(c) AgI
(d) CaC₂O₄·H₂O

3. The following concentrations are found in mixtures of ions in equilibrium with slightly soluble solids. From the concentrations given, calculate Ksp for each of the slightly soluble solids indicated:
(a) AgBr: [Ag⁺] = 5.7 × 10^-7 M, [Br-] = 5.7 × 10^-7 M
(b) CaCO₃: [Ca²⁺] = 5.3 × 10^-3 M, [CO32-] = 9.0 × 10^-7 M
(c) PbF₂: [Pb²⁺] = 2.1 × 10^-3 M, [F-] = 4.2 × 10^-3 M
(d) Ag₂CrO₄: [Ag⁺] = 5.3 × 10^-5 M, 3.2 × 10^-3 M
(e) InF3: [In³⁺] = 2.3 × 10^-3 M, [F-] = 7.0 × 10^-3 M

4. Calculate the molar solubility of AgBr in 0.035 M NaBr (Ksp = 5 × 10^-13).

Part -2:

1. A helium-filled balloon spontaneously deflates overnight as He atoms diffuse through the wall of the balloon. Describe the redistribution of matter and/or energy that accompanies this process.

2. Arrange the following sets of systems in order of increasing entropy. Assume one mole of each substance and the same temperature for each member of a set.
(a) H₂(g), HBrO₄(g), HBr(g)
(b) H₂O(l), H₂O(g), H₂O(s)
(c) He(g), Cl₂(g), P₄(g)

3. Predict the sign of the entropy change for the following processes.
(a) An ice cube is warmed to near its melting point.
(b) Exhaled breath forms fog on a cold morning.
(c) Snow melts.

4. "Thermite" reactions have been used for welding metal parts such as railway rails and in metal refining. One such thermite reaction is Fe₂O₃(s) + 2Al(s) ? Al₂O₃(s) + 2Fe(s). Is the reaction spontaneous at room temperature under standard conditions? During the reaction, the surroundings absorb 851.8 kJ/mol of heat. 25. Using the relevant S^°₂₉₈ values listed in Appendix G, calculate S°₂₉₈ for the following changes:

(a) N₂(g) + 3H₂(g) ? 2NH₃(g)
(b) N₂(g) + 5/2O₂(g) ? N₂O₅(g)