作者satisfy64ING (SATISFY)
看板NTU-Exam
標題[試題] 99上 王瑜 化學鍵 期中考
時間Fri Apr 22 17:58:54 2011
課程名稱︰化學鍵
課程性質︰化學系內選修
課程教師︰王瑜,鄭原忠
開課學院：理學院
開課系所︰化學系
考試日期（年月日）︰2011/4/22
考試時限（分鐘）：130
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
Chemical Bonding April 22, 2011
1. Construct the molecular orbitals (MO) of H2; LiH and HF respectively.
Compare the chemical bond (bond type; bond polarity and electron density
distribution) between these three compounds. (12)
2. For BeH2 AlH2 CH2 and 0H2 which ones are linear and which ones are bent,
why? Vhat about their mono-cation species?
The Walsh diagram of AH2 is given below. (12)
3. Construct the MOs of AH5 in trigonal bipyramid and in square pyramid
using basal and axial fragment approach; give qualitatively the MOs
(sign only) and their relative energies. (20)
4. Describe all the symmetry elements of point group C4 D3h and Td; the
character tables are given below. (26)
5. In the case of AH5 in C4. and D3h symmetry, work out the MOs for σ-bonding
of A-H using the result from question 3; what will be the hybrid orbitals
of A in each symmetry? (20)
6. Give the MOs (sign only) for six pπ-orbitals of benzene C6H6 according to
Huckel approximation the orbital energy is such that the lowest being
α+2β(1); then α+β(2); α-β(2); α-2β (1); (Number) in = # of
degenerate orbitals. Which ones are bonding and which ones are antibonding?
What are HOMO and LUMO? What is the resonance energy (stabilization energy
due to the delocalization) in terms of β; i.e. Total π-electron energy
of benzene subtract those of three isolated double bonds (2α+2β each).
(20)
7. Define the point group for each of following species: B(OH)3 PF5 BrF5
ferrocene Fe(η5-C5H5)2 Cr(η6-C6H6)2 benzene; p-difluoro-benzene;
m-difluoro-benzene. (8)
Character table for C4v point group
E 2C4 C2 σv(xz) σv(yz) linear, rotations quadratic
A1 1 1 1 1 1 z x^2+y^2, z^2
A2 1 1 1 -1 -1 Rz
B1 1 -1 1 1 -1 x^2-y^2
B2 1 -1 1 -1 1 xy
E 2 0 -2 0 0 (x,y) (Rx,Ry) (xz, yz)
Character table for D3h point group
E 2C3 3C'2 σh 2S3 3σv linear, rotations quadratic
A1'1 1 1 1 1 1 x^2+y2, z^2
A2'1 1 -1 1 1 -1 Rz
E' 2 -1 0 2 -1 0 (x,y) (x^2-y^2, xy)
A1"1 1 1 -1 -1 -1
A2"1 1 -1 -1 -1 1 z
E" 2 -1 0 -2 1 0 (Rx, Ry) (xz, yz)
Character table for Td point group
E 8C3 3C2 6S4 6σd linear, rotations quadratic
A1 1 1 1 1 1 x^2+y^2+z^2
A2 1 1 1 -1 -1
E 2 -1 2 0 0 (2z^2-x^2-y^2, x^2-y^2)
T1 3 0 -1 1 -1 (Rx, Ry, Rz)
T2 3 0 -1 -1 1 (x, y, z) (xy, xz, yz)
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◆ From: 140.112.250.115
※ 編輯: satisfy64ING 來自: 140.112.250.115 (04/22 17:59)
1F：推 firepeter :超快= = 04/22 19:31
2F：推 firepeter :建議下面的character table修一下 04/22 20:14
※ 編輯: satisfy64ING 來自: 140.112.250.115 (04/22 20:32)
3F：推 firepeter :辛苦了XD 04/22 21:37