Determine AG° for a reaction when AG = -152.0 kJ/mol and Q = 0.043 at 298 K. (R = 8.314 J/mol ·K)

For the reaction TiCl2(s) + Cl2(g) TiCl4(), rG = 272.8 kj/mol-txn. Using this value and other data available in Appendix L, calculate the value of fG for TiCl2(s).

Use the values of Hf in Appendix 4 to calculate H for the following reactions. (See Exercise 77 .) a. b. SiCl4(l)+2H2O(l)SiO2(s)+4HCl(aq) c. MgO(s)+H2O(l)Mg(OH)2(s)

9.96 Most first aid "cold packs" are based on the endothermic dissolution of ammonium nitrate in water: NH4NO3(s)NH4+(aq)+NO3(aq) H= 25.69 kJ A particular cold pack contains 50.0 g of NH4NO3 and 125.0 g of water. When the pack is squeezed, the NH4NO3dissolves in the water. If the pack and its contents are initially at 24.0°C, what is the lowest temperature that this bag could reach? (Assume that the ammonium nitrate solution has a specific heat of 4.25J g-l K-l, and that the heat capacity of the bag itself is small enough to be neglected.)

The value of G for the reaction 2C4H10(g)+13O2(g)8CO2(g)+10H2O(l) is 5490. kJ. Use this value and data from Appendix 4 to calculate the standard free energy of formation for C4H 10(g).

From the values for G f given in Appendix 1, calculate G at 25C for each of the reactions in Question 19.

Actually, the carbon in CO2(g) is thermodynamically unstable with respect to the carbon in calcium carbonate(limestone). Verify this by determining the standardGibbs free energy change for the reaction of lime,CaO(s), with CO2(g) to make CaCO3(s).

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

How much will the temperature of a cup (180 g) of coffee at 95 C be reduced when a 45 g silver spoon (specific heat 0.24 J/g C) at 25 C is placed in the coffee and the two are allowed to reach the same temperature? Assume that the coffee has the same density and specific heat as water.

Define the standard enthalpy of formation. What are standard states for elements and for compounds? Using Hess's law, illustrate why the formula Hreaction=npHf(products)nfHf(reactants) works to calculate H for a reaction.