Methanol (CH3OH) can be made by the reaction of COwith H2:CO(g) + 2 H2(g) ⇌ CH3OH(g) (a) calculate ΔH° for this reaction. (b) To maximize the equilibriumyield of methanol, would you use a high or low temperature?(c) To maximize the equilibrium yield of methanol,would you use a high or low pressure?

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.

Explain how the entropy of the universe increases when an aluminum metal can is made from aluminum ore. Thefirst step is to extract the ore, which is primarily a formof A12O3, from the ground. After it is purified by freeingit from oxides of silicon and iron, aluminum oxide ischanged to the metal by an input of electrical energy. 2Al2O3(s)electricalenergy4Al(s)+3O2(g)

Hydrogen gas and iodine gas react to form hydrogen iodide. If 0.500 mol H2 and 1.00 mol I2 are placed in a closed 10.0-L vessel, what is the mole fraction of HI in the mixture when equilibrium is reached at 205C? Use data from Appendix C and any reasonable approximations to obtain K.

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?)

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.)

Given the following data at 25C 2NO(g)N2(g)+O2(g)K=1 10 30 2NO(g)+Br2(g)2NOBr(g)K=8 101 Calculate K for the formation of one mole of NOBr from its elements in the gaseous state.

Consider the decomposition of CaCO3(s) into CaO(s) and Co2(g). What is the equilibrium partial pressure of CO2 at room temperature?

Silver carbonate, Ag2CO3, is a light yellow compound that decomposes when heated to give silver oxide and carbon dioxide: Ag2CO3(s)Ag2O(s)+CO2(g) A researcher measured the partial pressure of carbon dioxide over a sample of silver carbonate at 220C and found that it was 1.37 atm. Calculate the partial pressure of carbon dioxide at 25C. The standard enthalpies of formation of silver carbonate and silver oxide at 25C are 505.9 kJ/mol and 31.05 kJ/mol, respectively. Make any reasonable assumptions in your calculations. State the assumptions that you make, and note why you think they are reasonable.

At mom temperature, the equilibrium constant (Kw) for the self-ionization of water is 1.001014. Using this information, calculate the standard free energy change for the aqueous reaction of hydrogen ion with hydroxide ion to produce water. (Hint: The reaction is the reverse of the self-ionization reaction.)