21. Determine the ligand field stabilization energy of [Rh(H₂O)₆]³⁺.
(A)0△o
(B) -0.4△o 
(C)-1.9△o 
(D) -2.0 △o 
(E) -2.4 △o

17. Which of the following is a cyclic organic compound with four nitrogen atoms? (A) Tetrazine(B) Diazine (C) Triazine (D) Benenze (E) None of the above

18. Which of the following organic compounds with the sum formula CroH4 exhibits two singlets in the 'H NMR spectrum and three signals in the 3C NMR spectrum?(A)(B)(C)(D)(E) None of the above

19. What type of bonds hold the monomers in a typical polymer like PP together? (A) Ionic bonds (B) Hydrogen bonds (C) Covalent bonds (D) Hydrophobic interaction (E) Van der Waals interaction

20. Which of the following amino acids has a positively charged side chain under physiological conditions? (A) Alanine (B) Asparagine (C) Glutamine(D) Aspartate (E) Arginine

【已刪除】22. Determine the number of isomers for the [Co(NH3)2(H2O)2BrCl]+ complex. (A)3 (B)4 (C)5 (D) 6 (E) 7 

23. The reactionhas a reaction enthalpy of △H = 217 kJ mol-1, If the bond energy of a single phosphorus-phosphorus bond is 200 kJ mol-', how much is the bond energy of the bond? (A) 92 kJ mol-1(B) 192 kJ mol-1(C) 292 kJ mol-1(D) 392 kJ mol-1(E) 492 k)mol-1

24. Cisplatin is a well-known anticancer drug with the chemical formula Pt(NH3)2CI2. Which of the following statements is true? (A) Both Raman and IR spectra of cisplatin show two bands in the Pt-CI stretching region. (B) Only the Raman spectrum of cisplatin shows two bands in the Pt-CI stretching region； the IR spectrum does not show any bands in the Pt-Cl stretching region. (C) Only the infrared spectrum of cisplatin shows two bands in the Pt-CI stretching region； the Raman spectrum does not show any bands in the Pt-Cl stretching region. (D) Both Raman and IR spectra of cisplatin do not show any bands in the Pt-CI stretching region. (E) None of the above.

25. Which of the following is a measure of the randomness of a system in thermodynamics? (A) Energy (B) Pressure (C) Heat transfer (D) Work done(E) Entropy

26. What is the relationship between the activation energy and rate constant of a chemical reaction? (A) The rate constant is proportional to the negative activation energy. (B) The rate constant is inversely proportional to the negative activation energy. (C) As the activation energy decreases, the rate constant remains constant. (D) As the activation energy increases, the rate constant increases exponentially. (E) As the activation energy increases, the rate constant decreases exponentially.

27. Organic compounds can be classified based on their functional groups. Which of the following is not a functional group? (A) Isocyano (B) CarbonyI (C) Isocyanide (D) Carboxyl (E) None of the above