課程名稱︰普通化學乙上 General Chemistry (B)
課程性質︰必修
課程教師︰彭旭明
開課學院：
開課系所︰心理系 森林系
考試日期（年月日）︰2012年1月11日
考試時限（分鐘）：110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.Give the order in decreasing radius:(選項為離子)
(a)Be, Mg, Ba. (b)N3-, O2-, F-.(c)Tl3+, Tl2+, Tl+.(6%)
2.The formula for calculating the energies of an electron in a hydrogen like
ion is: E(n)=-(2.18x10^(-18)J) x Z^(2) x (1/N^(2))
This equation cannot be applied to many-electron atoms. One way to modify it
for the more conplex atoms is to replace Z with (Z-σ), in which Z is the
atomic number and σ is a positive dimensionless quantity called the shielding
constant. Consider the helium atom as an example. The physical significance
of σ is that it represents the extent of shielding that the two 1s electrons
exert on each other. Thus, the quantity (Z-σ) is appropriately called the
"effective nuclear charge." Calculate the value of σ if the first ionization
energy of helium is 3.94x10^(-18)J per atom.(Ignore the minus sign in the
given equation in your calculation.)(6%)
3.Match each of the elements on the right with its description on the left:
(a) A greenish-yellow gas
that reacts with water.
Nitrogen(N2)
(b) A soft metel that reacts
Boron(B)
with water to produce hydrogen.
Aluminum(Al)
(c) A metalloid that is hard
Fluorine(F2)
and has a high melting point.
Sodium(Na)
(d) A colorless, oderless gas.
(e) A more reactive metel than iron,
which does not corrode in air. (5%)
4.Draw the Lewis structure and sketch the molecular geometry of the following
molecules:
(a) H2SO4, (b) HNO3, (c)H3PO3 (One H is bonded to P), (d)CO, (e)O3, (f)SF4
(g)IF5, (h)SOF4, (i)SO3, (j)HN3 (azidic acid) (20%)
5.True or false:(4%)
(a) Formal charges represent actual separation of charges;
(b) ΔH0rxn can be estimated from bond enthalpies of reactants and products;
(c) All second-period elements obey the octet rule on their compounds;
(d) The resonance structures of a molecule can be separated from one another.
6.
(a)Draw three resonance structures of these two linear ions N3- and N5+
respectively, showing all their formal charges.(6%)
(b)Refer to the following table, please calculate the reaction enthalpy change
of the reaction: N5+ + N3-(g) → 4N2(g) [Assuming lattice energy is neglected]
(4%)
Bond Bond Enthalpy(kJ/mol)
N－N 193
N＝N 418
N≡N 941.4
7.Write the Lewis structures, bond orders, magnetic properties of O2,
O2+(O2的一價陽離子), O2-(O2的一價陰離子) and compare their bond length.(10%)
8.Sketch the shapes of these molecular orbitals: σ1s, σ1s*, π2p, and π2p*.
How do their energies compare?(8%)
9.Antimony Pentaflouride, SbF5, reacts with XeF4 and XeF6 to form ionic
compounds, XeF3+SbF6- and XeF5+SbF6-. Describe the geometries of the cations
and anion in these two compounds.(4%)
10.The allene molecule H2C＝C＝CH2 is linear (the three C atoms lie on a
straight line). What are the hybridization states of the carbon atoms? Draw
diagrams to show the formation of sigma bonds and pi bonds in allene.(6%)
11.Draw Newman projections of four different conformations of butane. Rank
them in stability.(Hint: Two of the conformations represent the most stable
forms and the other two the least stable forms.)(6%)
12.Draw all the possible isomers of C5H10 and name them.(10%)
13.Predict the products of each of these reactions:(6%)
(a)CH3CH2OH + HCOOH →
(b)H－C＝C－CH3 + H2 →
(c) C2H5 H
╲╴／
／￣╲ + HBr →
H H
14. Indicate the asymmetric carbon atoms in these compounds:
CH3 O
∣ ∥
(a) CH3－CH2－CH－CH－C－NH2
∣
NH2
(b) H
|
H C H
|╱|╲|
C Br C
| ￣￣|
H H
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