31. The standard enthalpy of formation of H₂O(I) at 300 K is -286 kJ/mol. Calculate the change in internal energy for the following process at 300 K and 1 atm: 

 2H₂O(I)→2H(g)+O₂(g)
(A) 278.5 kJ
(B) 282.3 kJ
(C)289.7kJ
(D) 564.5 kJ
(E) 579.5 kJ

27. Two isomers (A and B) of a given compound dimerize as follows:Both processes are known to be second order in the reactant, and ki is known to be . In a particular experiment A, and B were placed in separate container at 25 ℃,where and . After each reaction had progressed for 3.00 min, [A] = 3.00 [B]. In this case the rate laws are define as follows:The concentration of A2 after 3.00 min is x M. The half-life for the experiment involving B isy s. What are the values of x and y?(A)(B)(C) (D)(E)

28. Given the following two standard reduction potentials,  Determine for the standard reduction potential of the half-reaction (A) -0.33 V (B)-0.036V (C)-0.11V (D)0.11V (E) 0.33 V

29. The observed solubility of the salt MX in 4.0 M strong acid is . The K, value for the acid HX is . Calculate the value of for the salt MX. (A) (B) (C) (D) (E)

30. A galvanic cell is constructed with copper electrodes and in each compartment. In one compartment, , and in the other compartment, . Calculate the potential for this cell at 25  ℃. The standard reduction potential for is +0.34 V. (A) 0.43 V (B) -0.43 V (C) 0.092 V (D) -0.092 V (E) 0.77 V

32. A 0.50 M solution of the BHA has a pH of 7.50 at 25 ℃, where B is a weak base and A- is the anion of the weak acid HA. Ifthe K, value for B is , what is the Ke value for HA? (A)(B)(C)(D) (E)

33. What is in a solution of Ca(OH)z at 25 ℃? (A) (B) (C) (D) (E)

34. The heat of vaporization of water at the normal boiling point, 373 K, is 40.7 kJ/mol. The specific heat capacity of liquid water is and of gaseous water is . Assume that these values are independent of temperature. What is the heat of vaporization of water at 288 K? (A) 44.0 kJ/mol (B) 50.2 kJ/mol (C) 37.4 kJ/mol (D) 31.2 kJ/mol (E) 40.7 kJ/mol

35. The atomic mass is 2.01410 u for . The masses are 0.000549 u for electron, 1.00728 u for proton, and 1.00866 u for neutron. What is the binding energy per nucleon for ? (A) 1.12 MeV(B) 1.42 MeV (C) 2.24 MeV (D) 2.83 MeV (E) 5.66 MeV

複選題36. Consider 150 J of heat added to 40.4 g of Ne in a closed container at 0  ℃ and I atm. If the heat is transferred at constant pressure, which of the following statements are TRUE? (Assume that the gases behave ideally.) (A) The final temperature will increase. (B) The change in enthalpy (△H) is 150 J. (C) The change in internal energy (△E) is 90 J. (D) The work (w) is -60 J. (E) If the heat is transferred at constant volume in the above process, the change in enthalpy (△H) will be 250 J.

37. One mole of an ideal gas undergoes an isothermal reversible expansion at 300 K. During theprocess, the system absorbs 750 J of heat from the surroundings. When this gas iscompressed to the original state in one step isothermally, twice as much work is done on thesystem as was performed on the surroundings in the expansion. Which of the followingstatements are TRUE?(A) for the one-step isothermal compression is 2.5 J/K.(B) for the one-step isothermal compression is 5.0 J/K.(C) for the reversible isothermal expansion is zero.(D) for the overall process (expansion and compression) is zero.(E) for the overall process (expansion and compression) is -2.5 J/K.