課程名稱︰無機化學一 課程性質︰必修 課程教師︰鄭淑芬 開課學院：理學院 開課系所︰化學系 考試日期（年月日）︰2012/12/26 考試時限（分鐘）：110 是否需發放獎勵金：是 （如未明確表示，則不予發放） 試題 : 1.(a) Show the molecular orbital energy diagram of the diatomic molecule C2. Also, indicate the bonding, antibonding and non-bonding orbitals(if any). (6%) (b) The bond dissociation energy of C2 (599 kJ/mol) decreases slight on forming C2+ (513 kJ/mol) and increases greatly on forming C2- (818 kJ/mol). Why? (6%) 2.(a) Give the symmetry lables for the 4s-, 3d- and 4p-orbitals of the central metal atoms in [CoBrCl5]3-, trans- and cis-[CoCl2(en)2]+ (where "en" is "ethylenediamine"). (9%) (b) How many Co-Cl stretching vibration peaks do you expect to see in the IR spectra of these three ions, respectively? (15%) 3.(a) Work out the symmetry-adapted linear combinations of p-orbitals to form π-orbitals for cyclobutadiene. (8%) (b) Sketch the shapes of these π-orbitals. (4%) (c) Show the molecular orbital energy diagrm of the π-orbitals for cyclobutadiene. (2%) 4.(a) Utilizing simple Huckel M.O. theory with the p-orbitals which form π-orbitals of O3 as a basis set, set up the secular determinant and compute the energies of the π-orbitals of O3 in terms of α (Coulomb integral) and β (Overlap integral). (10%) (b) SO2 is isoelectronic to O3. Compare the energies of its π-M.O. with those of O3. (5%) (c) SO2 is both a Lewis acid and a Lewis base. When reacting with trimethyl amine, which orbital do you expect SO2 to use? and from S or from O atom sides? Explain. (5%) 5.(a) Show the molecular orbital energy diagrams and LCAOs for H3 in (i) linear and (ii) triangle planar geometries. (10%) (b) Draw the "Walsh diagram" for H3. (5%) (c) What will be the most stable geometries for H3+, H3, and H3- species, respectively? (3%) 6. Arrange the following ions in order of increasing acidity, and account for the trend. (10%) [Na(H2O)n]+, [Al(H2O)6]3+, [Mn(H2O)6]2+, [Fe(H2O)6]3+, [Ni(H2O)6]2+ 7.(a) What is the definition of "proton affinity"(PA)? Write the equation with NF3. (2%) (b) Write a thermochemical cycle from which you can obtain the "proton affinity" of NF3, from the bond dissociation energies of N-H in NF3H+, and ionization energies(IEs) of H and NF3. (5%) (c) Explain why the PA of NH3 is greater than that of PH3, based on the above cycle. (2%) (d) Explain why the difference in PAs between NH3 and NF3 is greater than that between PH3 and PF3. (5%) ------------------------------------------------------------------------------ Compound NH3 NF3 PH3 PF3 ------------------------------------------------------------------------------ PA(kJ/mol) 854 1122 789 910 IE of M in MX3 984 984 965 965 (kJ/mol) ------------------------------------------------------------------------------ Given information: Orbital Potential Energies(atomic number 1~36, 1s, 2s, 2p, 3s, 3p, 4s, 4p) Correlation Tables of D3h & Td Character table of C2, C3, C4, C2v, C3v, C4v, D3, D2h, D3h, D3d, Oh, Td --

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