推 husay :哇你超閒的....好強 01/16 15:02
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推 ken2002cool :n'<n-1打成n'=n-1了 01/16 17:14
課程名稱︰普通化學甲
課程性質︰必帶
課程教師︰許益瑞
開課系所︰農業化學系 大氣科學系 地質科學系
考試日期（年月日）︰Jan.-16th-2009
考試時限（分鐘）：140分鐘
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
1.Fish-liver oil is a good source of vitamin A, which is measured
spectrophotometrically at a wavelength of 329nm.
(a)In what region of the spectrum does this wavelength lie?(2 points)
(b)When 0.1232g of fish-liver oil is dissolved in 500.0 ml of solvent, the
absorbance is 0.724 units.When 1.67*10^-3g of vitamin A is dissolved in
250.0 ml of solvent, the absorbance is 1.018 units.
Calculate the vitamins A concerntration in the fish-liver oil.(8 points)
2.After we solved the Schrodinger equation of hydrogen atom, the quantized
energy and atomic orbital of 1s, 2s, and the 3s are given as following,
En=-h^2/(8π^2 Me a0^2 n^2)
(n=1,2,3......),h is Planck's costant, Me is the electron mass
and a0 is 0.5292 A
Ψ100(r)= 1/√π* (1/a0)^3/2 * e^-σ
Ψ200(r)= 1/4√2π* (1/a0)^3/2 * (2-σ)e^-σ
Ψ300(r)= 81/√3π* (1/a0)^3/2 * (2-18σ-2σ^2)e^-σ/3
σ=r/a0, a0 = 0.5292
please answer the question.
(a)What physical meaning is attributed to the square of the wave function,
|Ψ|^2 (3 points)
(b)Explain your own words it means for the peak in the radial probability
distribution 4πr^2*|Ψ100|^2 plot for the hydrogen 1s orbital at
a0=0.529A(3 points)
(c)If the electron moving near the atomic nuclear has a speed of
6*10^6m/s ±1%.What is the uncertainty in its position?(4 points)
(d)According to the result of(c), do you think we can precisely locate the
electron? Explain your answer.(4 points)
(e)How many nodes you can find in Ψ100,Ψ200 andΨ300?(3 points)
(f)Find the ΔE between n=2 and n=3, and its corresponding wavelength?
(4point)
3.(a)Draw the H2 Molecular Orbital (MO) diagrams( 5points)
(b)Use the MO diagram in (a) to predict whether H2+ and H2- exist?
Determine their bond order and electron configuration (6 points)
4.Nitrogen monoxide (NO) is an odd electron molecule with a vital biochemical
function. Heating NO can convert it to N2O and NO2.
(a)Please write down and balance the chemical reaction.(3 points)
(b)Please write down the most stable Lewis structure of N2O, and its
oxidation state of each N, and explain the molecular shape N2O by VSEPR
theory(6 points)
(c)NO2 has many resonance forms. Please drow two Lewis resonance structure
with one lone electron and one double bond, and assign the formal charge
to each atomin these two structure.(3 points)
(d)If two NO2 collide to form N2O4, please draw the Lewis structure of N2O4
and explain which form in (c) is more important in this reaction.
(4 points)
(e)Please draw the Lewis structure of nitronium ion (NO2+) and nitrite ion
(NO2-).(4 points)
(f)Please use VSEPR theory to explain the bond angle differences among
NO2+, NO2, NO2- .(6 points)
5.Draw the molecular shapes and predict the bond angles (relative the ideal
angle ) of (i)COCl2(ii)SF2(iii)S2F2(iv)SOF4(v)BrF5
(2 poimts for each)
6.Please draw the following orbital shapes.(The horison and vertical axes
should be labeled. )(10 points)
(a)Px(b)Pz(c)dxy(d)dx2-y2(e)dxz
7.(a)Rank the ion in each set in order of increasing size and explain your
reason.(i)Li+,K+,Na+(ii)O2-,F-,N3-(3 points for each one)
(b)Arrange the following set in order of increasing bond strength:
(i)H-Br,H-Cl,H-I(ii)C-C,C=C,C≡C (3 points for each one)
(c)Rank the members of each set of compounds in order of increasing ionic
character of their bonds.
Use polar arrows to indicate the bond polarity of each:
(i)HBr,HCl,HI (ii)H2O,CH4,HF (iii)SCl2,PCl3,SiCl4 (3 points for each one)
8.The treatment of partical in a one-dimentional box can be extended to a
rectangular box of dimensions Lx,Ly,Lz, yielding the following expression
of energy:
E=h^2/8m * (nx2/Lx2+ny2/Ly2+nz2/Lz2)
The three quantum number nx,ny,nz independently can assume only interger
values.
(a)Determine the energies of the three lowerest levels, assuming that the
box is cubic.(3 points)
(b)Describe the degeneracies of all the levels that correspond to quantum
numbers having value of 1 or 2. How will these degeneracies change in
a box where LX≠ LY≠ LZ(3 points)
9.(a)Write the condensed ground-state electron configuration of these
transitions metal ions, and the state which are paramagnetic or
diamagnetic ions:
(i)Co2+ (ii)Mn2+ (iii)Mo3+(3 points)
(b)Some chemist found that the ClO2-,ClO-,Cl- can form CuClO2, CuClO and
CuCl2.
(i)What is the oxidation number of Cu in each compounds? Which copper
ion is a paramagnetic ion?(3 points)
(ii)What is the oxidation number of Cu in each compound?(3 points)
(iii)In order to estimate the effective nuclear charge Zeff=Z-σ,where
Z is the atomic number and σ is the screen constants, Slater gave
empirical method to estimate the screen constant,σ.
For an electron in an orbital with principal quantum number n, the
screen effect is mainly from the other electron with quantum number
less or equal to n. According to his rule, we can make a summery
table as follow,(10 points)
┌──────┬──────┬──────┬──────┬──────┐
│ │n'=n-1 │n'=n-1 │n'=n │ n'>n │
├──────┼──────┼──────┼──────┼──────┤
│1s │ │ │0.30 │0 │
├──────┼──────┼──────┼──────┼──────┤
│ns,np │1 │0.85 │0.35 │0 │
├──────┼──────┼──────┼──────┼──────┤
│nd,nf │1 │1 │0.35 │0 │
└──────┴──────┴──────┴──────┴──────┘
For example, Z=15, 1s2 2s2 2p6 3s2 3p3
An electron in n =2, theσ2s2p=2*0.85+7*0.35=4.15, so that
Zeff= 15- 4.15= 9.85
According to this rule, please calculate the Zeff of an electron
with n=3 of all Cl in three compounds.
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