複選題
12. Which of the following groups contains the molecules that do not have a same point group?
(A) CO₂ and C₂H₂
(B) PCls and BF₃
(C) POCl₃ and NH₃
(D) SO₂F₂ and H₂O
(E) CH₄ and XeF₄ COOH

8. Which has the greatest molar heat of combustion? (A) trans-1,2-dimethylcyclopentane (B) cis-1,2-dimethylcyclopentane (C) trans-1,3-dimethylcyclopentane (D) methylcyclohexane (E) cycloheptane

9.Which of the following reagents is used to protect the amino group of the N-terminal residue in solution-phase peptide synthesis? (A) benzyl chloroformate (B) lithium diisopropyl amide (C) phenyl isothiocyanate (D) dicyelohexylcarbodiimide (E) trifluoroacetic acid

10. What is the major end product of the following reaction series? (A) Ala (B) Gly (C) Leu (D) Ile (E) Val

11. Treatment of a peptide which contains disulfide linkages with peroxyformic acid yields a peptide which contains what new amino acid residue? (A) cystine (B) cysteic acid (C) 4-hydroxyproline (D) y-alanine (E) methioic acid

13. Which of the following species is optically active? (A) NH2C1 (B) (C) (D) SiFCBrI (E) HCN

14. What is the purpose of a moderator surrounding the uranium cylinder in a nuclear (fission)reactor core?(A) To slow down the neutrons(B) To accelerate the neutrons(C) To produce a particles(D) To absorb B particles(E) To absorb the neutrons

15. Which of the following instruments is/are used to detect and measure radioactivity levels?I. Geiger counterII. Richter scaleIII. Seismic scaleIV. Scintillation counter(A) I only (B) III only (C)I&IV (D)I&I(E) I, I, II&IV

16. How many of the following ligands are capable of linkage isomerism? (A) 1 (B) 2 (C) 3 (D) 4 (E) 5

17. You analyze for pyridine () by dissolving 0.1000 g of the complex in 100 mL of H2O and titrating with a 0.01 M HCI solution. Which of the following indicators should be used to detect the endpoint? (Assume that the initial concentration of pyridine is approximately 0.01 M.) (A) thymol blue, pH range of color change = 8.0-9.6 (B) methyl red, pH range of color change = 4.8-6.0 (C) bromophenol blue, pH range of color change = 3.0-4.6 (D) bromothymol blue, pH range of color change = 6.0-7.6 (E) alizarin yellow, pH range of color change = 10.1-12.0

18. Which of the following is paramagnetic? (A) (B) (C)(D)(E