1. What is the value of H° for this reaction? 1 Fe2O3(s) + 3 H₂O(1) ? 2Fe(OH)3(s) Hof (kJ mol ¹) Fe2O3(s) -824.2 Fe(OH)3(s) -823.0 H₂O(1) -285.8

Predict whether each of the following processes results in an increase in entropy in the system. (Define reactants and products as the system.) (a) Water vapor condenses to liquid water at 90 C and 1 atm pressure. (b) The exothermic reaction of Na(s) and Cl2(g) forms NaCl(s). (c) The endothermic reaction of H2 and I2 produces an equilibrium mixture of H2(g), I2(g), and HI(g). (d) Solid NaCl dissolves in water forming a saturated solution.

The following reaction occurs in pure water: H2O(l)+H2O(l)H3O+(aq)+OH-(aq) which is often abbreviated as H2O(l)H+(aq)+OH-(aq) For this reaction, G = 79.9 kJ/mol at 25C. Calculate the value of G for this reaction at 25C when [OH] = 0.15 M and [H+] = 0.71 M.

Consider the reaction NH4+(aq) H+(aq)+NH3(aq) Use G f for NH3(aq) at 25C=26.7 kJ/mol and the appropriate tables to calculate (a) G at 25C (b) Ka at 25C

The equilibrium constant for a certain reaction increases by a factor of 6.67 when the temperature is increased from 300.0 K to 350.0 K. Calculate the standard change in enthalpy (H) for this reaction (assuming H is temperature-independent).

Consider the equilibrium system HF(aq)H+(aq)+F(aq) Given HfHF(aq)=320.1kJ/mol , HfF(aq)=332.6kJ/mol ; SF(aq)=13.8kJ/molK ; KaHF=6.9104 at 25°C calculate S° for HF(aq).

Wet limestone is used to scrub SO2 gas from the exhaust gases of power plants. One possible reaction gives hydrated calcium sulfite: CaCO3(s) + SO2(g) + H2O() CaSO3 H2O(s) + CO2(g) Another reaction gives hydrated calcium sulfate: CaCO3(s) + SO2(g) + H2O() + O2(g) CaSO4 H2O(s) + CO2(g) (a) Which reaction is more product-favored at equilibrium? Use the data in the table below and any other information needed in Appendix L to calculate rG for each reaction at 25 C. (b) Calculate rG for the reaction CaSO3 H2O(s) + O2(g) CaSO4 H2O(s) Is this reaction product- or reactant-favored at equilibrium?

Is Ssurr favorable or unfavorable for exothermic reactions? Endothermic reactions? Explain.

Write a chemical equation for each process and classify each as reactant-favored or product-favored. (a) A puddle of water evaporates on a summer day. (b) Silicon dioxide (sand) decomposes to the elements Silicon and oxygen. (c) Paper, which is mainly cellulose (C6H10O5)n, bums at a temperature of 451 F. (d) A pinch of sugar dissolves in water at room temperature.

Sodium chloride is added to water (at 25C) until it is saturated. Calculate the Cl concentration in such a solution. Species G(kJ/mol) NaCl(s) 384 Na+(aq) 262 Cl(aq) 131