45. For which of the following metal ions would there be no distinction between low spin and high spin in octahedral complexes?
(A)
(B)
(C)
(D)
(E)

41. Which statement regarding water is true? (A) liquid water is less dense than solid water.(B) only covalent bonds are broken when ice melts (C) hydrogen bonds are stronger than covalent bonds (D) energy must be given off in order to break down the crystal lattice of ice to a liquid (E) all of these statements are false.

42. Which of the following is the smallest hole in a closest-packed lattice of spheres? (A) trigonal (B) cubic (C) tetrahedral (D) octahedral (E) none of these

43. The unit cell in a certain lattice consists of a cube formed by an anion at each corner, an anion in the center, and a cation at the center of each face. The unit cell contains a net (A) 2 anions and 3 cations (B) 2 anions and 2 cations (C) 5 anions and 3 cations (D) 3 anions and 4 cations (E) 5 anions and 6 cations.

44.How many of the following compounds exhibit geometric isomers? I: Pd(NHa3)2Br2 (square planar)； Il:[Co(H2O)2]Br3； I1:[Ni(H2O)4(NO2)2]； lV:K2[CoCl4] (A) 2(B) 3 (C) 1 (D) 4(E)0

46. Which of the following stateme ents is true of the crystal field model? (A) the electrons are assumed to be localized (B) the metal ion-ligand bonds are considered completely ionic (C) the ligands are treated as negative point charges (D) the interaction between metal ion and ligand is treated as a Lewis acid-base interaction (E) none of these statements is true

47. A d6 ion is complexed with six strong-field ligands (for example, SCN-). What is the number of unpaired electrons in this complex? (A) 3(B) 2 (C)0(D) 1(E) 4

48. Which of the following state nts are true about starch? I: the mono omers are fructose and Rlucose； Il: the mon onomer is glucose； Ill: it is the main carbohydrate reservoir in plants； IV: It is the main carbohydrate reservoir in animals； V: It is an addition polymer； VI. It is a condensation polymer. (A) II, III, VI (B) I, IV, V (C) I, II, IV, V (D) I, II, V (E) II, IV, VI

49. Which of the following pairs of substances could form an addition copolymer? (A) HOCH2CH2OH + HOOCH2COOH(B) HOOC(CH2)3COOH + HOCH2CH2CHANH2 (C) HOOCCH2CH2COOH + HOCH2OCH2 OH (D) H2C=CHCH=CH2 +H2CCH=CHCH3 (E) H2NCH2 COOH + H2NCH2CH2COOH

50. Which of the following statements is/are true of benzene? I: Benzene belongs to a class of cyclic unsaturated hydrocarbons known as the aromatic hydrocarbons；II : Benzene undergoes substitution reaction in which hydrogen atoms are replaced by other atoms； Ill: sp2 hybrid orbitals on each carbon of a benzene molecule are used to form the H-H and H-C a bonds. (A) IIl only (B) II only (C) I only (D) I and Il (E) I and Ill

1. 下列哪組是大氣中含量最豐富的氣體？ (A) O2, Ne (B) N2, O2 (C) CO2, O2 (D) He, CO2