課程名稱︰物理化學
課程性質︰必修
課程教師︰戴子安
開課學院：工學院
開課系所︰化工系
考試日期（年月日）︰102.5.13
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.(30%)Explain the following terms. Use graph if necessary.
(a)Plot a representative potential energy surface diagram for a reaction
A+BC-->AB+C at a fixed angle of approach.
(b)Two primary assumptions used in the transition state theory.
(c)The Eyring equation.
(d)The relationship between the Arrhenius parameters and the Eyring parameters
(△H++ and △S++)for a bimolecular gas phase reaction.
(e)The Beer-Lambert's law.
(f)Singlet and triplet states for reaction.
(g)Schematically illustrate the absorption/relaxion/emission process for a
diamatic molecule under light exposure.
(h)Schematically illustrate and name all processes occuring in T1 to S0
transition.
(i)Fluorescence resonance energy transfer.
(j)Describe one mechanism that chlorofluorocarbon(CFC) destorys ozone.
2.(10 points)A 100cm^3 vessel containing hydrogen and chlorine was irradiated
with light of 400nm. Measurments with a thermopile showed that 11x10^-7 J of
light energy was absorbed by the chlorine per second. During an irradiation
of 1min the partial pressure of chlorine, as determined by the absorption
of light and the application of Bee's law, decreased from 27.3s to 20.8kPa
(corrected to 0℃). What is the quantum yield?(The Planck constant, h=6.626x
10^-34 Js)
3.(10 points)Based on the hard-sphere model, derive the expression for the
rate constant of the reaction, k
B1+B2------>P, by assuming that the reaction
occurs upon the first collision.(The collision diameter for the two reactant
is assumed to be d12.)
4.(10 points)The unimolecular decomposition of urea in aqueous solution is
measured at two different temperatures and the following data are observed:
Trial number Temperatue(℃) k(s^-1)
1 60.0 1.2x10^-7
2 71.5 4.4z10^-7
(a)Determine the Arrehenius parameters for this reaction.
(b)Using these parameters, determine △H++ and △S++ as described by the
Eyring equation at T=60℃.
5.(10 points)For phenanthrene, the measured lifetime of the triplet state(τp)
is 3.3s, the fluorescence class at 77k. Assume that no quenching and no
internal conversion from the singlet state occurs. Determine kp, kT ISC,
kS ISC/kF.
6.(10 points) The mechanism for formation and destruction of ozone can be
explained as follows:
(a) JO2
O2+hv1---------->2O
(b) k2
O+O2+M---------->O3+M
(c) JO3
O3+hv2---------->O2+O
(d) k4
O3+O------------>2O2
Derive the steady state concentration of ozone and explain why the
concentration occurs at some altitude on earth.
7.(10 points)The phosphorescence of butyrophenone in acetionitrile is quenced
by 1,3-pentadiene(P). The following quantum yields were measured at 25℃.
[P]/10^-3 mol/L 0 1.0 2.0
ψ/ψ0 1 0.61 0.43
Assuming that the quenching reaction is diffusion controlled and the rate
constant has a value of 10^10 L/mol．s, what is the lifetime of the triplet
state?
8.(10 points)Consider the formation and decay of an excited state
Absorption S0+hv1--->S1 v=Ia(assumeψ=1)
kF
Fluorescence S1------>S0+hv2
kIC
Inernal conversion S1---------->S0+hv2
kISC
Intersystem crossing S1---------->T1
kQ
Collisional quenching S1------------>S0+Q
Derive the expression for the fluorescence lifetime, Stern-Volmer equation,
and the quantum yield for fluorescence.
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 140.112.247.183