14. Lake Titicaca is located high in the Andes Mountains between Peru and Bolivia. Its surface is 3811 m above sea level, where the average atmospheric pressure is 0.636 atm. During the summer, the average temperature of the water’s surface rarely exceeds 15 °C. What is the solubility of oxygen in Lake Titicaca at that temperature? Express your answer in molarity and mg/L.CH12
15. Which of the following processes is/are spontaneous?(a) A tornado forms.(b) A broken cell phone fixes itself.(c) You get an A in this course.(d) Hot soup gets cold before it is served. 16. Without consulting reference sources, select the component that has a greater standard molar entropy at 298 K. 17. Use the standard molar entropies in Appendix 4 to calculate the ΔS° value for each of the following reactions of sulfur compounds.(a) H2S(g) + (3/2) O2(g) ⟶ H2O(g) + SO2(g)18. The following reaction plays a key role in the destruction of ozone in the atmosphere:Cl(g) + O3(g) → ClO(g) + O2(g)The standard entropy change (ΔS°rxn) is 19.9 J/(mol ∙ K). Use the standard molar entropies (S°) inAppendix 4 to calculate the S° value of ClO(g).19. The value of ΔSrxn of a spontaneous reaction D + E ⟶ F is 72.0 J/K. What is the minimum value of the entropy change in thereaction’s surroundings?20. Consider the reaction of nitrogen gas and hydrogen gas (Figure 12.15) at 298 K to make ammonia at the same temperature:N2(g) + 3 H2(g) → 2 NH3(g)a. Before doing any calculations, predict the sign of ΔS°rxn.b. What is the actual value of ΔS°rxn?c. What is the value of ΔH°rxn?d. What is the value of ΔG°rxnat 298 K?e. Is the reaction spontaneous at 298 K and 1 bar of pressure?Is this reaction spontaneous only at low temperatures, only at high temperatures or at all temperatures? What is the minimum temperature at which this process is spontaneous?21. Use the data in Appendix 4 to calculate ΔH° and ΔS° for the vaporization of hydrogen peroxide:H2O2(ℓ) → H2O2(g)Assuming that the calculated values are independent of temperature, what is the boiling point ofhydrogen peroxide at P = 1.00 atm?CH1322. Consider the reaction4NO2(g) + O2(g) → 2N2O5(g)The initial rate of change in the concentration of NO2is -0.00130 M/s. (a)What are the initial rates of change in the concentrations of O2 and of N2O5(b)At what rate is O2being consumed? At what rate is N2O5being produced?23. Rate = k[O3][NO](a)Determine the rate constant of this reaction.(b)In a 4thexperiment, the initial concentrations of O3 and NO are 0.0020 M. What would be the initial rate in this experiment? ?
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