課程名稱︰普通化學乙下
課程性質︰系必帶
課程教師︰金必耀 副教授
開課學院：理學院
開課系所︰化學系開給土木系
考試日期（年月日）︰99/06/25
考試時限（分鐘）：120+30min
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
General Chemistry II Final Examination 6/25/2010
1.(6%) Consider the ammonia synthesis reaction N2(g)+3H2(g)→2NH3(g)，where
ΔG0=-33.3kJ per mol of N2 consumed at 25 C. For each of the following
mixtures of reactants and products at 25 C, predict the direction in which the
system will shift to equilibrium.
(a) P(NH3)=1.00atm P(N2)=1.47atm P(H2)=1.00x10^(-2)atm
(b) P(NH3)=1.00atm P(N2)=1.00atm P(H2)=1.00atm
2.(5%) The overall reaction for the corrosion (rusting) of iron by oxygen is
4Fe(s) + 3O2(g) → 2Fe2O3(s)，calculate the equilibrium constant for the
reaction at 25 C using the following data.
Substance ΔH0f(kJ/mol) ΔS0(J/mol-K)
Fe2O3(s) -826 90
Fe(s) 0 27
O2(g) 0 205
3.(4%) Simply describe Le Chatelier's principle and how to predict
qualitatively the change or shift of the equilibrium constant as the
temperature of the endothermic or exothermic reaction changes. (hint: you
should interpret in words and illustration.)
4.(4%) Show and shortly derive van't Hoff equation. Is there the similar
tendency between van't Hoff equation and Le Chatelier's principle.
5.(8%) Benzene has a melting point of 5.5 C and the enthalpy of fusion of
10.04kJ/mol. The molar heat capacities at constant pressure for solid and
liquid benzene are 100 and 133 J/mol-K, respectively. For the reaction:
C6H6(l) →←(雙向反應@@) C6H6(s), calculate ΔSsys and ΔSsurr at 11.0 C at
constant pressure.
6.(6%) Consider the system: A(g) →← B(g) at 25 C.
a. Assuming that G0A= 8996 J/mol and G0B= 11718 J/mol, calculate equilibrium
constant.
b. Calculate the equilibrium pressure that result if 1.00 mol A gas at 1.00
atm and 1.00 mol B gas at 1.00 atm are mixed at 25 C.
7.(7%) A quantitative measure of how efficiently spheres pack into unit cells
is called packing efficiency, which is the percentage of the cell space
occupied by the spheres. Calculate the packing efficiencies of a simple cubic
cell, a body-centered cubic cell, and a face-centered cubic cell.(Hint: the
volume of a sphere is 4πr^3/3, where r is the radius of the sphere.)?
8.(7%) Briefly describe the differences among insulator , semiconductor, and
conductor using the energy band picture? State whether silicon would form
n-type or p-type semiconductors with the following element: Ga, Al, As
9.(7%) The properties of crystalline solids are determined largely by intermo-
lecular interactions. Explain why diamond is harder than graphite. Why is
graphite an electrical conductor but diamond is not?
10.(9%) Given the phase diagram of carbon shown below, answer the following
questions:
(a) How many triple points are there and what are the phases that can coexist
at each tiple point?
(b) Which has a higher density, graphite or diamond?
(c) Synthetic diamond can be made from graphite. Based on the phase diagram,
how would you do this?
(附圖是一張碳的三相圖)
11.(8%) The following diagram shows the variation of the equilibrium constant
with temperature for the reaction: I2(g) →← 2I(g). Calculate ΔG0, ΔH0, and
ΔS0 for the reation at 872K.
12.(6%) Show that the half-time of a second-order reation is given by
t1/2=1/k[X]0. In what fudamental way does the half-life of a second-order
reation differ from a first-order reation?
13.(6%) The reation 2N2O5(g) → 4NO2(g) + O2(g) was studied at several
temperatures and the following values of k were obtained. Calculate the value
of Ea for this reation.
T(C) 20 30 40 50 60
k(s^(-1)) 2.0x10^-5 7.3x10^-5 2.7x10^-4 9.1x10^-4 2.9x10^-3
14.(9%) The chart show the relationhsip of reation pathway and free energy
(kJ/mol) at 300K.
a. What is the intermediate? What will it happen if catalyst adds? What does D
and E stand for? A→C is exo- or endothermic reation? What is the
rate-determing step?
b. Calculate the ΔG0 and K for the overall reaction.
c. Set the two defferences of energy between A to D and B to E as the
activation energies of each. Calculate the rate constant of the overall
reation. (Arrhenius factor of the reactoin is 2.11x10^5 s^-1)
15.(8%) The reation 2NO + O2 → 2NO2 exhibits the rate law: Rate=k[NO]^2[O2].
Which of the following mechanism is consistent with this rate law?
a. NO + O2 → NO2 + O slow
O + NO → NO2 fast
b. NO + O2 →← NO3 fast equilibrium
NO3 + NO → 2NO2 slow
c. 2NO → N2O2 slow
N2O2 + O2 → 2N2O4 fast
N2O4 → 2NO2 fast
d. 2NO →← N2O2 fast equilibrium
N2O2 → NO2 + O slow
O + NO → NO2 fast
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其中10. 11. 14. 題是有圖的，不過不知道圖片有沒有版權，在此就不附上了
不過題目還是留著給大家參考
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