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Chemistry 106: General Chemistry
Syracuse University Project Advance
Exam #2, Fall 2003
Name
Date
The last page of each examination is a periodic table.
c = 3.00 x 108 m/sec
h = 6.63 x 10-34 Js
mp = 1.67 x 10-24 g (mass of proton)
Rydberg Constant (RH) = 2.18 x 10-18 J
(1)
Hydrogen peroxide, H2O2, can be prepared in a process whose overall change is:
H2(g) + O2(g) ------> H2O2(l)
Calculate the enthalpy change for the reaction above using the following data.
H2O2(l) ------> H2O(l) + 1/2 O2
2 H2(g) + O2(g) ------> 2H2O (l)
(a)
(b)
(c)
(d)
(e)
(2)
H
H
= -98.0 kJ
= -571.6 kJ
-670 kJ
-474 kJ
-523 kJ
-384 kJ
-188 kJ
Ethanol (molar mass = 46.05 g/mol), C2H5OH, is mixed with gasoline and sold as
gasohol. Use the following to calculate the grams of ethanol needed to provide
293 kJ of heat:
C2H5OH(l) + 3 O2(g) ------> 2 CO2(g) + 3 H2O(g)
(a)
(b)
(c)
(d)
(e)
CHE 106
H
= -1235 kJ
10.9 g
21.8 g
32.7 g
43.6 g
54.5 g
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Fall 2003 Exam Questions
(3)
Phosphoric acid, H3PO4, can be prepared by the reaction of phosphorus(V) oxide,
P4O10, with water
1/4 P4O10(s) + 3/2 H2O(l) ------> H2PO4(aq)
H
= -113.2 kJ
What is H for the reaction involving 1 mol of P4O10?
(a)
(b)
(c)
(d)
(e)
(4)
Which one of the following will have the greater kinetic energy?
(a)
(b)
(c)
(d)
(5)
+113.2 kJ
+28.3 kJ
-28.3 kJ
-452.8 kJ
-905.6 kJ
A 10 kg object traveling at 5 m/s.
a 5 kg object traveling at 10 m/s.
both of these have the same kinetic energy.
not enough information is provided to answer the question.
Given that Hf for MgCl2 is -641.6 kJ/mol and Hf for KCl is -435.9 kJ/mol,
calculate Hrxn for the following equation:
2 K(s) + MgCl2(s) ------> 2 KCl(s) + Mg(s)
(a)
(b)
(c)
(d)
(e)
(6)
=?
+205.7 kJ
-205.7 kJ
+230.2 kJ
-230.2 kJ
+1077.5 kJ
A chemical reaction that absorbs heat from the surroundings is said to be
and has a
value of H.
(a)
(b)
(c)
(d)
(e)
(7)
Hrxn
endothermic, positive
endothermic, negative
exothermic, negative
exothermic, positive
isothermic, zero
Which of the following has the longest wavelength?
(a)
(b)
(c)
(d)
CHE 106
an electron traveling at x meters per second.
a proton traveling at x meters per second.
a proton traveling at 2x meters per second.
they all have the same wavelength.
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Fall 2003 Exam Questions
(8)
(e) not enough information is provided.
Which of the following sets of quantum numbers is/are possible for an electron in
an atom?
n = 4, l = 4, ml = 3, ms = +1/2
n = 1, l = 0, ml = 0, ms = -1/2
n = 2, l = 0, ml = -2, ms = +1/2
I.
II.
III.
(a)
(b)
(c)
(d)
(e)
(9)
Indium compounds emit a blue-violet color when placed in a flame. The emission
responsible for this blue-violet color has a wavelength of 451 nm. Calculate the
energy of a single photon of this wavelength.
(a)
(b)
(c)
(d)
(e)
(10)
2.99 x 10-40 J
1.47 x 10-27 J
4.41 x 10-19 J
2.99 x 10-31 J
1.47 x 10-36 J
How many unpaired electrons are in a ground state atom of phosphorus?
(a)
(b)
(c)
(d)
(e)
(11)
None are possible
I and II
I
II
III
0
1
2
3
None of the above.
The number of core electrons shielding the valence-shell electrons of an atom of
aluminum from the nucleus is:
(a)
(b)
(c)
(d)
(e)
CHE 106
13
10
6
3
0
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Fall 2003 Exam Questions
(12)
Calculate the energy (joules per particle) of a photon of wavelength 22.5 nm
(Plancks Constant is 6.63 x 10-34 Js)
(a)
(b)
(c)
(d)
(e)
(13)
What is the wavelength of light emitted when the hydrogen atom undergoes a
transition from level n = 5 to level n = 2? (RH = 2.180 x 10-18 J)
(a)
(b)
(c)
(d)
(e)
(14)
describes the energy of the electron.
specifies the momentum for the electron.
gives the probability of finding the electron in a region of space.
is proportional to the velocity of the electron.
is inversely proportional to the distance between the electron and the
nucleus.
From the Bohr model of the hydrogen atom, we can conclude that the energy
required to excite an electron from the n = 2 to the n = 3 level is
the
energy to excite an electron from the n = 3 to the n = 4 level.
(a)
(b)
(c)
(d)
(e)
(16)
663 nm
833 nm
546 nm
521 nm
434 nm
The square of the wavefunction, 2, of an electron in an atom
(a)
(b)
(c)
(d)
(e)
(15)
1.13 x 1017
1.13 x 1013
8.84 x 10-11
8.84 x 10-18
None of the above.
less than
greater than
equal to
either equal to or less than
either equal to or greater than
All of the following statements about quantum numbers are true except
(a)
(b)
(c)
(d)
(e)
CHE 106
n has integral values from 1 to infinity.
l has values from 1 to infinity.
ml has 2l + 1 values
ml has values of +1 to -1, including zero.
ms has values of + 1/2 and - 1/2.
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Fall 2003 Exam Questions
(17)
Which of the following combinations of quantum numbers are permissible?
I.
II.
III.
(a)
(b)
(c)
(d)
(e)
(18)
ms
-1/2
-1/2
+1/2
3
5
7
9
18
Sr
Mg
P
I
Ne
Which of the following atoms designated by electronic configuration has the
highest ionization energy?
(a)
(b)
(c)
(d)
(e)
(21)
ml
1
1
1
Which of the following atoms has the smallest atomic radius?
(a)
(b)
(c)
(d)
(e)
(20)
l
3
2
2
What is the maximum number of electrons in the n = 3 quantum level?
(a)
(b)
(c)
(d)
(e)
(19)
n
3
4
3
I only
II only
III only
I and II only
II and III only
[Ne] 3s23p2
[Ne] 3s23p3
[Ar] 3d104s24p3
[Kr] 4d105s25p3
[Xe] 4f145d106s26p3
Which one of the following elements would be expected to have the largest atomic
radius?
(a)
(b)
(c)
(d)
(e)
CHE 106
Li
Cs
F
Br
I
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Fall 2003 Exam Questions
(22)
In general, atomic radii
(a)
(b)
(c)
(d)
(e)
(23)
All of the following is isoelectronic except
(a)
(b)
(c)
(d)
(e)
(24)
decrease from left to right in a period and increase down a group.
increase from left to right in a period and decrease down a group.
increase from left to right in a period and increase down a group.
decrease from left to right and decrease down a group.
None of the above.
S2Ar
K+
Cl-1
Na+
Which of the following statements about the alkali metals (Group 1) is not correct?
(a) Electron affinities decrease going down the group (from smaller to
larger elements).
(b) Ionization energies decrease going down the group (from smaller to
larger elements).
(c) Chemical reactivity decreases going down the group (from smaller to
larger elements).
(d) The second ionization energy for each one is much greater than the first
ionization energy.
(e) Each one can attain a noble gas configuration by losing an electron.
CHE 106
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Fall 2003 Exam Questions