作者satisfy64ING (SATISFY)
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标题[试题] 99上 王瑜 化学键 期中考
时间Fri Apr 22 17:58:54 2011
课程名称︰化学键
课程性质︰化学系内选修
课程教师︰王瑜,郑原忠
开课学院：理学院
开课系所︰化学系
考试日期（年月日）︰2011/4/22
考试时限（分钟）：130
是否需发放奖励金：是
（如未明确表示，则不予发放）
试题 :
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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※ 发信站: 批踢踢实业坊(ptt.cc)
◆ From: 140.112.250.115
※ 编辑: satisfy64ING 来自: 140.112.250.115 (04/22 17:59)
1F：推 firepeter :超快= = 04/22 19:31
2F：推 firepeter :建议下面的character table修一下 04/22 20:14
※ 编辑: satisfy64ING 来自: 140.112.250.115 (04/22 20:32)
3F：推 firepeter :辛苦了XD 04/22 21:37