課程名稱︰普通化學丙
課程性質︰醫學系大一必帶
課程教師︰陳逸聰
開課學院：醫學院
開課系所︰醫學系
考試日期（年月日）︰2013/11/06
考試時限（分鐘）：180
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
1. Naturally occurring rubidium (Rb) consists of two isotopes: Rb-85 (atomic
mass 84.9117) and Rb-87 (atomic mass 86.9092). The atomic mass of the isotope
mixture found in nature is 85.4678. Calculate the percentage abundances of the
two isotopes in rubidium.(4%)
o
2. The electron in a hydrogen atom is initially at a distance 2.12A from the
o
proton, and then moves to a distance 0.529A from the proton.
(a) Calculate the change in the force between the proton and the electron.(3%)
(b) Calculate the change in the potential energy between the proton and the
electron.(2%)
(c) Calculate the change in the velocity of the electron.(3%)
3. Estimate the percent ionic character of the bond in the diatomic molecule of
o
ClO, based on its dipole moment of 1.239D and bond length of 1.573A.(3%)
- -
4. For (a) PF and (b) ClO , give the steric number and sketch and name the
6 2
approximate molecular geometry according to VSEPR. In each case, the central
atom is listed first and the other atoms are all bounded directy to it.(4%)
5.
(a) Give systematic names of Al O and KHCO .(4%)
2 3 3
(b) Write the chemical formulas for silver cyanide and ammonium carbonate.(4%)
6. Two possible Lewis diagrams for sulfine(H CSO) are
2
Ｈ .. .. Ｈ .. .. ..
>Ｃ＝Ｓ－Ｏ: >Ｃ－Ｓ＝Ｏ:
Ｈ .. Ｈ
(a) Compute the formal charges on all atoms.(4%)
(b) Draw a Lewis diagram for which all the atoms in sulfine have formal charges
of zero.(2%)
2
7. Radio waves of wavelength 6.00*10 m can be used to communicate with
spacecraft over large distances.
(a) Calculate the frequency of these radio waves.(2%)
(b) Suppose a radio message is sent home by astronauts in a spaceship
10
approaching Mars at a distance of 8.0*10 m from Earth. How long (in minutes)
will it take for the message to travel from the spaceship to Earth?(2%)
8.
(a) In developing a theoretical model to interpret the spectrum of hydrogen
atom, Niels Bohr postulated that the angular momentum is quantized,
h
L = m vr = n--- (n=1,2,3,...) eq.(1)
e 2π
Using equation (1) to derive the radius of the n-th quantum state to be
2 2
εn h
0 2
r = ------ = n a . eq.(2)
n 2 0
πe m
e
2
εh
0 o
Where a = ------ = 0.529A is called Bohr radius.(6%)
0 2
πe m
e
+
(b) He ions are observed in stellar atomspheres. Use the Bohr model to
+
calculate the radius and the energy of He in the n = 5 state.(4%) How much
+
energy would be required to remove the electrons from 1 mol of He in this
state?(2%) What frequency and wavelength of light would be emitted in a
transition from the n = 5 to the n = 3 state of this ion? Express all results
in SI units.(4%)
9. Calculate the de Broglie wavelength of electrons that have been accelerated
7 -1
to a kinetic energy of 1.20*10 J mol .(4%)
10.When metallic sodium is dissolved in liquid sodium chloride, electrons are
released into the liquid. These dissolved electrons absorb light with a
wavelength near 800nm. Suppose we treat the positive ions surrounding an
elecron crudely as defining a three-dimensional cubic box of edge L, and we
assume that the absorbed light excites the electron from its ground state to
the first excited state. Calculate the edge length L in this simple model.
2 2
n h
(Hint: The energy for one-dimensional particle-in-a-box is E = ----)(5%)
2
8mL
1 1
11.Suppose that the spin quantum number had three allowed values(m = 0,+-,--).
s 2 2
Give the atomic numbers of the first two noble-gas atoms in this case.(4%)
12.Quantum mechanics predicts that the energy of the ground state of the H atom
is -13.6eV. Insight into the magnitude of this quantity is gained by
considering several methods by which it can be measured.
(a) Calculate the longest wavelength of light that will ionize H atoms in their
ground state.(3%)
(b) Assume the atom is ionized by collision with an electron that transfer all
its kinetic energy to the atom in the ionization process. Calculate the speed
of the electron before the collision. Express your answer in meters per second
-1
(m s ).(3%)
(c) Calculate the temperature required to ionize an H atom in its ground state
by thermal excitation. (Hint: Recall the criterion for thermal excitation of an
oscillator in Planck's theory of blackbody radiation is that hν≒ k T.)(2%)
B
13.Photoelectron spectroscopy studies have determined the orbital energies for
chlorine atoms to be
1s -2835eV
2s -273eV
Estimate the value of Z for Cl in 1s and 2s orbitals.(4%)
eff
14.Terminology, description, and illustration (if necessary).
(a) Describe how the charge-to-mass and the charge of the electron were
determined in the experiments by J.J.Thomson and R.Millikan, respectively.(8%)
(b) Mulliken's and Pauling's electronegativity scales.(4%)
(c) Dissociation energy of a molecule.(2%)
(d) Indeterminacy (uncertainty) principle.(4%)
(e) Why chromium oxide (CrO ) is a good compound to fabricate magnetic
2
recording tapes?(4%)
(f) 最近之假油風波，因觸及公共衛生安全與國人身體健康之嚴重性，引起社會大眾之廣
泛關注與憤怒。據報導，在此假油事件中，花生油內無花生，橄欖油內無橄欖，食用油被
摻雜棉籽油，導致棉籽油內是否含有棉酚，因而可能致病之疑慮...。事實上，只要具備正
確及充實的化學知識，真油與假油是可檢測分辨出來。如果你是檢驗人員，請問你有何方
法、或工具可做此分辨？並請描述你所列舉之方法、或工作之工作原理，為何其有能力分
辨？(10%)
棉酚之分子結構：
http://ppt.cc/bKM-
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