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a Calculate K1, at 25C for sulfurous acid: H2SO3(aq)H+(aq)+HSO3(aq) b Which thermodynamic factor is the most significant in accounting for the fact that sulfurous acid is a weak acid? Why?

Is the reaction Si(s) + 2 H2(g) SiH4(g) spontaneous under standard conditions at 298.15 K? Answer this question by calculating S(system), S(surroundings), and S(universe). (Define reactants and products as the system.)

Use data from Appendix D to calculate the standardentropy change at 25°C for the reaction CH3COOH(g)+NH3(g)CH3NH2(g)+CO2(g)+H2(g) Suppose that 1.00 mol each of solid acetamide, CH3CONH2(s), and water, H2O(l), react to give thesame products. Will the standard entropy change belarger or smaller than that calculated for the reactionin part (a)?

One of the important reactions in the biochemical pathway glycolysis is the reaction of glucose-6-phosphate (G6P) to form fructose-6-phosphate (F6P): G6PF6PG298=1.7kJ (a) Is the reaction spontaneous or nonspontaneous under standard thermodynamic conditions?. (b) Standard thermodynamic conditions imply the concentrations of G6P and F6P to be 1 M, however, in a typical cell, they are not even Close to these values. Calculate G when the concentrations of G6P and F6P are 120 M and 28 M respectively, and discuss the spontaneity of the forward reaction under these conditions. Assume the temperature is 37 C.

Predict whether each reaction is reactant-favored or product-favored at 298 K and 1 bar, and calculate the minimum work that would have to be done to force it to occur, or the maximum work that could be done by the reaction. (a) 2 CO2(g) 2 CO(g) + O2(g) (b) 4 Fe(s) + 3 O2(g) 2 Fe2O3(s)

Calculate the standard Gibbs free-energy change when SO3 forms from SO2 and O2 at 298 K. Why is sulfur trioxide an important substance to study? (Hint: What happens when it combines with water?)

Coal is used as a fuel in some electric-generating plants. Coal is a complex material, but for simplicity we may consider it to be a form of carbon. The energy that can be derived from a fuel is sometimes compared with the enthalpy of the combustion reaction: C(s)+O2(g)CO2(g) Calculate the standard enthalpy change for this reaction at 25C. Actually, only a fraction of the heat from this reaction is available to produce electric energy. In electric generating plants, this reaction is used to generate heat for a steam engine, which turns the generator. Basically the steam engine is a type of heat engine in which steam enters the engine at high temperature (Th), work is done, and the steam then exits at a lower temperature (Tl). The maximum fraction, f, of heat available to produce useful energy depends on the difference between these temperatures (expressed in kelvins), f = (Th Tl)/Th. What is the maximum heat energy available for useful work from the combustion of 1.00 mol of C(s) to CO2(g)? (Assume the value of H calculated at 25C for the heat obtained in the generator.) It is possible to consider more efficient ways to obtain useful energy from a fuel. For example, methane can be burned in a fuel cell to generate electricity directly. The maximum useful energy obtained in these cases is the maximum work, which equals the free-energy change. Calculate the standard free-energy change for the combustion of 1.00 mol of C(s) to CO2(g). Compare this value with the maximum obtained with the heat engine described here.

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).

The formation of aluminum oxide from its elements is highly exothermic. If 2.70 g Al metal is burned in pure O2 to give A12O3, calculate how much thermal energy is evolved in the process (at constant pressure).