33. Consider the following system at equilibrium:  Which of the following changes will shift the equilibrium to the right? I. increasing the temperature II. decreasing the temperature I IE. increasing the volume TV. decreasing the volume V. removing some NH₃, VI. adding some NH₃ VII removing some N₂ VII I. adding some N₂
(A)  
(B)
(C) 
(D) 
(E)

29. A method of separation that employs a system with two phases of matter, a mobile phase and a stationary phase, is called ! (A) filtration. (B) chromatography. (C) distillation. (D) vaporization. (E) homogenization.

30. You take an aspirin tablet (a compound consisting solely of carbon, hydrogen, and oxygen) with a mass of 1.00 g，bum it in air, | and collect 2.20 g of carbon dioxide and 0.400 g water. The molar mass of aspirin is between 170 and 190 g/mol. The molecular E form of aspirin is c (A) C6H8O5 (B) C9H8O4 (C)C8H10O5 (D)C10H6O4 (E) none of these 

31 • Which of the following electrode could be a reference electrode except g (A) SHE (B)NHE (C) SCE (D)Ag/AgCl (E) all of above 

32. The light source of fluorescence measurements and detector is usually at j； (A) 30 (B) 60 (C) 90 (D) 120 (E) 180 degrees. 

34. If, at a given temperature, the equilibrium constant for the reaction  is Kp, then the equilibrium constant for the reactioncan be represented as: (A) (B)  (C) (D) (E) none of above

35. The value of the equilibrium constant, K, is dependent on | . The temperature of the system. II • The nature of the reactants and products. Ill. The concentration of the reactants. IV. The concentration of the products. (A)丨，|| (B) II，III (C) III，IV (D) It is dependent on three of these choices. (E) It is not dependent on any of these choices.

36. Which of the following would produce a basic aqueous solution? (A)P4O10 (B)KC1 (C) C02 (D) NH4C1 (E) none of these

37. Which of the following will not produce a buffered solution? (A) 100mLof0.1MNa2C03and50mLof0.1 MHC1 (B) 100 mL of 0.1 MNaHCO3, and 25 mL of 0.2M HC1 (C) 100 mL of 0.1 M Na2CO3, and 75 mL of 0.2 M HC1 (D) 50 mL of 0.2 M Na2CO3 and 5 mL of 1.0 M HC1 (E) lOOmLofO.l MNa2C03 and50mLof0.1 MNaOH

38. In the titration of a weak acid HA with 0.100 M NaOH the stoichiometric point is known to occur at a pH value of approximately 10. Which of the following indicator acids would be best to use to mark the endpoint of this titration? (A) indicator A, 10-14 (B) indicator B,iTa= 10-11  (C) indicator C,Ka= 10-8 (D) indicator D, Ka = 10-6 (E) none of these

39. Silver acetate (AgC2H3O2)is a sparingly soluble salt with Ksp = 1.9 ✖ 10- 3. Consider a saturated solution in equilibrium with the solid salt. Compare the effects on the solubility of adding to the solution either the acid HNO3, or the base NH3. (A) Either substance would decrease the solubility. (B) NH3 would increase the solubility, but HNO3, would decrease it. (C) NH3 would increase the solubility, but HN03 would have virtually no effect. (D) Either substance would increase the solubility. (E) NH3 would decrease the solubility, but HN03 would increase it. .