Download 09 Exam 1 Key

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1. (24)a. Number the following types of light from lowest (#1) to highest (#4) frequency.
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- 1-infrared
-
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---,-t./-_uv
visible
b. Number the following elements from lowest (#1) to highest
3
- -CI
I
radio
(#4)~. ~oYV\lc... ("~d; u.s
K
Ca
c. What is the maximum number of electrons in an atom that can be described with the quantum
numbers n=3, 1=2, ml= -2
cl.
3d
x
~~
d. What element has the following valence electron configuration in an excited state?
1...- --±- i.t t :L 1
4s
3d
e. Give the number of unpaired electrons in the ground state electron configuration of Cr:
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3d
f. How many electrons and protons , respectively, are in ~~ Kr
a) 36 , 56
b) 56 , 36
c) 92,36
d) 36,92
e) 56 , 92
@6, 36
g. Underline the compound with the shortest C-C bond . Circle the compound with the longest C-C
bond. ' Ie.,
~£,
'+Y,p\~ CH 3 CH 3 ~
CH 2 CH 2
FCCF h. The formula of a salt is XCI 2 . The X-ion in this salt has 28 electrons. The metal X is
2.
~oVide names or formulas for the following compounds: PCI,
a
strontiu m cyanide
5 (' (c /',j) :l-
Zn
fbO¥haraus -Ir;cJJav,~
Fe( BrQ, h
In"" (.(!;:j p?d.'1JlY1tde.
3. (12) Draw two resonance contributors for H2 CN 2 (connectivity shown below) that have all octets filled.
~ \ of" 1 to Lj + 10 ~
Circle the most favorable . l:- ".fc.
Ita vo..1e..nc.e. e ~Jc
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H--C--N--N:
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H
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,
..
f:) c- i\i ::.~r
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N-=-~·
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3
4. (12) Complete the table.
~F5+
KrF4
. . ".
:P-i<.r
.. ,-, -F·
..
Most favorable Lewis structure
'f.'
0-
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F-S-F
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f/ '-r'"­
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Electron pair geometry name
Molecular geometry name
oc+o..~roJ
gDD
Sketch of shape, including
lone pairs.
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r,.,,,,
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Kr
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b;f'lrCAffi4dJ
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Bond angle
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5. (10)
.,
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-1"
a. Construct a molecular orbital diagram for C2".
b. Rank in terms of increasing bond strength: C2". C 2 , and C2 + .:;...
c. Where you listed your ranking, circle any compound that is paramagnetic. ~
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-
,
L.f
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6. (6).What is the ratio of the second ionization energy of He to the first ionization energy of H? Show the
z..a 2.­
equation you used as the basis of your answer.
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7. (8) Fill in the blanks with a word from the following list of possibilities. The
of?l'Y),1 ~f
eJt-c.+v &Y)
a d~'r'\j
of an element is the energy change upon an electron to an atom in the gas phase, forming a(n)
value means the ion is stable, and in general, these values become
(Y\
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left to right across the periodic table. In another periodic trend, atomic radii
proceed left to right across a row. Cations are
HALOGENS
ZERO
EL.£C:mGN-
REMOVING
LEAST
CATION
LARGER
LEFT
AF~
SOLUTION
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. A (leg a+fv€!..­
CU1 i orJ
negative as we move
d.e..c.reQ $;;:6s we
than their parent atoms.
SMALLER
IONIZATION ENERGY
POSITIVE
Arn1tNG
RIGHT
ANtOf\r
N!;cATI'v'E
MORE­
LESS
MOST
~
CONSTANT
SAME LESS
8. (6) Define these terms as used in chemistry:
a. Lewis acid -
b. Precision -
e: pr Q~ du.v ft'J
Qn
L-Vt1/ilhl \l'ah!u shdJ
rqx-a.fa..bt!.Jy cfP- ~~
A
9. (6) Silver has two isotopes, with masses 106.9051 g/mol and 108.9048 g/mol.
a. Use your periodic table to find the relative abundance of each isotope. (Don't do the math--­
just write the equation and fill in the numbers you would enter into your calculator).
-:: ( rr;o A " I0l9.c105~
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(IDO-'%~).
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-=%B
b. Show how you would calculate the mass of 100,000 bromine atoms.
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