Given that the standard enthalpy of formation of Hl(aq) is 55 kJ mol1, what is the value of fH (I, aq)?

If nitric acid were sufficiently heated, it can be decomposed into dinitrogen pentoxide and water vapor: 2HNO3(l)N2O5(g)+H2O(g)Hrxn=+176kJ (a) Calculate the enthalpy change that accompanies the reaction of 1.00 kg HNO3 (). (b) Is heat absorbed or released during the course of the reaction?

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).

Which of the following quantities can be taken to be independent of temperature? independent of pressure? (a) H for a reaction (b) S for a reaction (c) G for a reaction (d) S for a substance

Benzoic acid, C6H5COOH, is a common standard used in bomb calorimeters, which maintain a constant volume. If 1.20 g of benzoic acid gives off 31, 723 J of energy when burned in the presence of excess oxygen and in a water bath having a temperature of 24.6 C, calculate q, w, H, and U for the reaction.

Determine the standard Gibbs free energy change, rG, for the reactions of liquid methanol, of CO(g), and ofethyne, C2H2(g), with oxygen gas to form gaseous carbondioxide and (if hydrogen is present) liquid water at298 K. Use your calculations to decide which of thesesubstances are kinetically stable and which are thermodynamically stable: CH3OH(), CO(g), C2H9(g), CO2(g),H2O().

Another step in the metabolism of glucose, which occurs after the formation of glucose6-phosphate, is the conversion of fructose6-phosphate to fructose1,6-bisphosphate(bis meanstwo): Fructose6-phosphate(aq) + H2PO4(aq) fructose l,6-bisphosphate(aq) + H2O() + H+(aq) (a) This reaction has a Gibbs free energy change of +16.7 kJ/mol of fructose6-phosphate. Is it endergonic or exergonic? (b) Write the equation for the formation of 1 mol ADP fromATR for which rG = 30.5 kJ/mol. (c) Couple these two reactions to get an exergonic process;write its overall chemical equation, and calculate theGibbs free energy change.

Would the amount of heat absorbed by the dissolution in Example 5.6 appear greater, lesser, or remain the same if the heat capacity of the calorimeter were taken into account? Explain your answer.

What are the two ways that a final chemical state of a system can be more probable than its initial state?

When 1.000 g of ethylene glycol, C2H6O2, is burned at 25C and 1.00 atmosphere pressure, H2O(l) and CO2(g) are formed with the evolution of 19.18 kJ of heat. a Calculate the molar enthalpy of formation of ethylene glycol. (It will be necessary to use data from Appendix C.) b Gf of ethylene glycol is 322.5 kJ/mol. What is G for the combustion of 1 mol ethylene glycol? c What is S for the combustion of 1 mol ethylene glycol?