課程名稱︰普通化學丙
課程性質︰
課程教師︰彭旭明
開課學院：
開課系所︰
考試日期（年月日）︰95/10/20
考試時限（分鐘）：120
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
1. (A) The following aqueous solutions are common laboratory acids. What are
their names? (a) HCl(aq); (b) H2SO4(aq); (c) HNO3(aq); (d) CH3COOH(aq);
(e) H2SO3(aq); (f) H3PO4(aq). (6%)
(B) Name each of the following compounds: (a) Na2SO3; (b)Fe2O3; (c) FeO; (d)
Mg(OH)2; (e) NiSO4˙6H2O; (f) PCl5; (g) Cr(H2PO4)3; (h) As2O3; (i) RuCl2.
2. For a hydrogen atom in its ground state, calculate the relative probability
of finding the electron in the area described. (10%)
1 1 3/2 -r/a0
Ψ = — ( — ) e , a0 = 52.9pm
1s √π a
(a) in a sphere of volume 1.0*10^-3 pm^3 centered at the nucleus.
(b) in a sphere of volume 1.0*10^-3 pm^3 centered on a point 1.0*10^-11 m
from the nucleus.
(c) in a sphere of volume 1.0*10^-3 pm^3 centered on a point 52.9 pm from
the nucleus.
(d) in a shell between two concentric spheres, one with radius 9.95 pm and
the other with radius 10.05 pm.
(e) in a shell between two concentric spheres, one with radius 52.85 pm and
one with radius 52.95 pm.
3. (a) How many nodes are there for each of 1s, 2s, 3s orbitals? Draw the
electron probability distribution for 1s, 2s, 3s orbitals.
(b) Draw the electron probability distribution for 2pz, 3pz orbitals.
(c) Suppose that you begin at a distance far from the nucleus on the
z axis, through the nucleus to a distance far on the -z axis. How many
nodal surfaces would you pass through for each of following orbitals:
1s, 2s, 3s, 2pz, 3pz. (10%)
4. In 1999, Karl Christe synthesized and characterized a salt that contained
the N5+ cation. This cation is the first all-nitrogen species to be
isolated in more than 100 years. Draw the most important Lewis structure
for this ion, including all equivalent resonance structures. Calculate
the formal charges on all atoms and predict the shape of the ion. (6%)
5. Draw the Lewis structures and on the basis of their Lewis structures,
place the following molecules or ions in order of decreasing bond length:
(a) the CO bond in CO, CO2, CO3 2-; (b) the SO bond in SO2, SO3, SO3 2-;
(c) the CN bond in HCN, CH2NH, CH3NH2.
6. (a) The NO in smog can react with NO2. Draw the Lewis structure of the most
likely product.
(b) The NO2 in smog also reacts with NO3. Draw the Lewis structure of the
most likely product.
(c) Write the balanced chemical equation for the reaction of the product
from part (b)(an acidic oxide) with water. What secondary pollutant is
produced in this reaction?
7. Draw the Lewis structure and describe the three-dimensional structure of
the following molecules. (10%)
(a) NH3; (b) HN3; (c) H2SO4; (d) HNO3; (e) SF4.
8. (a) Draw the molecular orbital energy-level diagram for N2 and label the
energy levels according to the type of orbitals from which they are made,
whether they are σ- or π-orbitals and whether they are bonding or
antibonding.
(b) The orbital structure of the heterodiatomic ion CN- is similar to that
of N2. How will the fact that the electronegativity of C differs from that
of N affect the molecular orbital energy-level diagram of CN- compared with
that of N2?
Use this information to draw the energy-level diagram of CN-.
(c) In the molecular orbitals, will the electrons have a higher probability
of being at C or N? Why? (10%)
9. Which of the following species are paramagnetic: (a) O2; (b) O2-; (c) O2+?
If the species is paramagnetic, how many unpaired electrons does it
possess? (7%)
10.It is usually convenient to deal with wavefunctions that are "normalized",
which means that the integral ∫Ψ^2 dx = 1. The bonding orbital in
Ψ = ΨA1s + ΨB1s is not normalized. A wavefunction Ψ can be normalized
by writing it as NΨ and finding the factor N which ensures that the
integral over (NΨ)^2 is equal to 1. Find the factor N that normalizes the
bonding orbital in Ψ = ΨA1s + ΨB1s, given that the individual atomic
orbitals are each normalized. Express your answer in terms of the
"overlap integral" S = ΨA1sΨB1s dτ. (8%)
11.An organic compound distilled from wood was found to have a molar mass of
32.04 g/mol and the following composition by mass: 37.5% C, 12.6% H, and
49.9% O. (4%)
(a) Write the Lewis structure of the compound and determine the bond angles
about the carbon and oxygen atoms.
(b) Give the hybridization of the carbon and oxygen atoms.
(c) Predict whether the molecule is polar or not.
12.Acetylene (ethyne), C2H2 can be polymerized. (8%)
(a) Draw the Lewis structure for acetylene and draw a Lewis structure for
the polymer that results when acetylene is polymerized. The polymer has a
formula (CH)n, where n is large.
(b) Consider the polymers polyacetylene and polyethylene. The latter has
the formula (CH2)n and is an insulating material (plastic wrap is made of
polyethylene), whereas polyacetylene is a darkly colored material that can
conduct electricity when properly treated. On the basis of your answer to
part (a), suggest an explanation for the difference in the two polymers.
13.In addition to forming σ and π types of bonds similar to p-orbitals, d-
orbitals may overlap to form δ-bonds. (6%)
(a) Draw overlap diagrams showing three different ways in which d-orbitals
can combine to form bonds.
(b) Place the three types of d-d bonds--σ, π and δ--in order of
strongest to weakest.
14.Construct the molecular orbital energy-level diagram for linear H3 molecule
and label the energy levels according to the type of orbitals from which
they are made, whether they are bonding, nonbonding or antibonding. (6%)
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