42. A liquid-liquid solution is called an ideal solution if I: it obeys PV = nRT； II: it obeys Raoult's law； IIl: solute-solute, solvent-solvent, and solute-solvent interactions are very similar； IV: solute-solute, solvent-solvent, and solute-solvent interactions are quite different.
(A) II, IV
(B) II, III
(C) I, I
(D) I, 1, 111
(E) I, U, IV

38. The solubility of the salt. The osmotic pressure exhibited by a solution saturated with Mx,Ay, at 25℃ is 1.22 atm. Determine the values of x and y by assuming ideal behavior. (A) x = 1, y=3 (B) x= 27y = 5 (C) x = 1, y= 1 (D) x= 2 y = 3 (E) none of these

39. A cucumber is placed in a concentrated salt solution. What is most likely to happen? (A) salt will precipitate out (B) water will flow from the solution to the cucumber (C) salt will flow into the cucumber (D) water will flow from the cucumber to the solution (E) no change will occur

40. Liquid A has vapor pressure x. Liquid B has vapor pressure y, and x ＞ y. What is the mole fraction of A in the liquid mixture if the vapor above the solution is 50% A? (A) y/(2x + 2y) (B) y/(x+ y) (C) x/(2x + 2y) (D) x/(x + y) (E) none of these

41. Rank the following compounds according to increasing solubility in water. I: CH3-CH2-CH2-CH3；ll: CH3-CH2-O-CH2-CH3； III: CH3-CH2-OH； IV:CH3-OH (A) I＜Il＜IV＜III (B) I ＜III＜IV＜I (C)I＜II＜III＜IV(D) III＜IV＜lI＜I (E) none is correct.

43. How many unpaired electrons are found in (A) 0(B) 4 (C) 1(D) 5(E) 2

44. Which of the following statements about the complex ion Co(en)2Cl2+ (en = ethylenediamine, NH2CH2CH2NH2)is true? (A) the geometric isomers of the complex ion have identical chemical properties (B) the complex ion exhibits two geometric isomers (cis and trans) and two optical isomers (C) because en is a strong field ligand (large A), the complex ion is paramagnetic (D) the complex ion exhibits cis and trans geometric isomers, but no optical isomers (E) the complex ion contains Co(l)

45. The spectrochemical series is Which of the following complexes will absorb visible radiation of the highest energy? (A) (B) (C)(D)(E)

46. Which of the following complexes would be diamagnetic? (A)(B) (C) (D)(E) Fel(CO)5

47. Which has the greater number of unpaired electrons? I: square planar (A) I (B) II (C) neither I nor II has any unpaired electrons (D) more information is needed (E) both I and I| have the same (nonzero) number of unpaired electrons

48. When heat is added to proteins, the hydrogen bonding in the secondary structure breaks apart. What are the algebraic signs of△H and△S for the denaturation process? (A)△H is negative and △S is positive (B) both △H and△S are negative (C) △H is positive and △S is O (D) both △H and △S are positive (E) △H is positive and△S is negative