Chemistry 106: General Chemistry
Syracuse University Project Advance
Exam #3, Fall 2004
Name
(1)
Date
Write Lewis dot structures for the following substances: H2O, N2, NH3. There are
a total of 26 valence electrons. In your structures, how many nonbonding pairs
(lone pairs) of electrons are there?
(a)
(b)
(c)
(d)
(e)
(2)
When we can write several equivalent but different resonance structures for a
molecule, it means that, in the molecule,
(a)
(b)
(c)
(d)
(e)
(3)
The molecule is ionic.
One or more bonds are delocalized.
There is no way to give all the atoms octets of electrons.
The d electrons of one atom are involved.
There is at least one triple bond present.
Which atom would be expected to be the most electronegative?
(a)
(b)
(c)
(d)
(e)
(4)
1
2
3
4
5
B
Na
N
Cs
Al
Which pair of elements would form the most ionic bond?
(a)
(b)
(c)
(d)
(e)
CHE 106
H and O
O and F
Cs and S
S and Li
Al and N
1
Fall 2004 Exam #3
(5)
In the Lewis structure for CIF3, the number of lone pairs of electrons around the
central atom is
(a)
(b)
(c)
(d)
(e)
(6)
0
1
2
3
4
Which of the following statements is incorrect?
I.
The valence electrons are the lowest energy electrons of an atom in its ground
state.
II. The valence electrons are responsible for the chemistry of the atom.
III. The valence electrons are furthest, on average, from the nucleus of the atom.
IV. The configuration of the core electrons of an atom often resembles the
electron configuration of a noble gas.
(a)
(b)
(c)
(d)
(e)
(7)
I
II
III
IV
all are correct
Which of the following statements is/are incorrect?
I. The Lewis symbol for an oxygen atom is O
II. The electron configuration for Ni3+ is 1s22s22p63s23p63d84s2
III. The Lewis symbol for P3- is
(a)
(b)
(c)
(d)
(e)
(8)
I
II
III
I and II
II and III
All the following molecules have polar bonds and are polar molecules EXCEPT
(a)
(b)
(c)
(d)
(e)
CHE 106
ClF3.
PF3.
PF5.
SF4.
CH3F.
2
Fall 2004 Exam #3
(9)
The Lewis structure for phosphine, PH3, has
(a)
(b)
(c)
(d)
(e)
(10)
What is the formal charge on the chlorine atom in the chlorate ion, ClO3-, which is
drawn showing only three single bonds.
(a)
(b)
(c)
(d)
(e)
(11)
trigonal planar
one unshared pair of electrons on P
sp3-hybridized phosphorus atom
polar molecule
nonpolar molecule
(a)
(b)
(c)
(d)
(e)
1, 3, and 5
2, 3, and 4
1, 2, and 4
2, 3, and 5
1, 2, and 5
When a carbon atom has sp3 hybridization, it has
(a)
(b)
(c)
(d)
(e)
(13)
+2
+1
0
-1
-2
Which response contains all the characteristics listed that should apply to PF3?
1.
2.
3.
4.
5.
(12)
four bonding pairs
two bonding pairs and two lone pairs
three bonding pairs and one lone pair
one bonding pair and three lone pairs
four lone pairs
four  bonds.
three  bonds and one  bond.
two  bonds and two  bonds.
one  bond and three  bonds.
four  bonds.
At standard conditions, 2.75 L of a gas weighed 5.39 g. The gas is
(a)
(b)
(c)
(d)
(e)
CHE 106
N2
N2O
NO
F2
NF3
3
Fall 2004 Exam #3
(14)
An empty 2.0 L soda bottle is tightly capped with 2g of N2 inside. If the bottle is
placed in water at 95°C, what is the pressure in the bottle?
(a)
(b)
(c)
(d)
(e)
(15)
A mixture of .500 moles of ethanol vapor C2H5OH(g) and .500 moles of water
H2O(g) are contained within a 30.00 L container at 102°C. Both gases are
considered to be non ideal. Using van der Waals equation what is the total
pressure within this container?
(a)
(b)
(c)
(d)
(e)
(16)
.512 atm
.510 atm
1.53 atm
1.02 atm
2.02 atm
A sample of nitrogen gas at 18°C and 760 mm Hg has a volume of 2.67 mL. What
is the volume at 0°C and 1 atm of pressure?
(a)
(b)
(c)
(d)
(e)
(17)
520 mmHg
780 mmHg
820 mmHg
930 mmHg
2800 mmHg
2.85 mL
1.42 mL
1.50 mL
2.00 mL
2.50 mL
Which of the following statements is/are incorrect?
I.
If liquid “kryptonite” (from Superman’s home planet), with a density twice
that of mercury, is used in a barometer on earth, one standard atmosphere of
pressure would support a column of kryptonite 380 mm in height.
II.
At constant volume and number of moles of gas, the pressure exhibited by an
ideal gas is directly proportional to its absolute temperature.
III.
At standard temperature and pressure (STP), the volume of a mixture of gases
containing 0.400 mol H2, 0.600 mol N2, and 1.00 mol O2 is 44.8 liters and the
mole fraction of N2 is 0.300.
(a)
(b)
(c)
(d)
(e)
CHE 106
III
II
I
I and III
All are correct
4
Fall 2004 Exam #3
(18)
Decreasing the volume of a gas at constant temperature increases the pressure
(Boyle’s Law) because
(a)
(b)
(c)
(d)
the molecules collide with each other more often
the molecules are speeded up by collisions with the container walls
the molecules collide with the walls of the container more often
the molecules hit the walls of the container harder (with more
momentum)
(e) the molecules tend to stick to the walls of the container longer
(19)
You have a tank of argon gas at 19.8 atm pressure and 19°C. The tank’s volume is
50.0 L. What would be the volume of the gas if it expanded to 0.974 atm, with the
temperature maintained at 19°C?
(a)
(b)
(c)
(d)
(e)
(20)
Ammonium sulfate, used as a fertilizer, is produced by reacting ammonia with
sulfuric acid, according to: 2NH3(g) + H2SO4(aq)  (NH4)2SO4(aq). What
volume of ammonia gas at 15°C and 1.15 atm is required to produce 150.0 g of
ammonium sulfate? Molar masses: NH3, 17.0 g/mol; H2SO4, 98.0 g/mol,
(NH4)2SO4, 132.0 g/mol.
(a)
(b)
(c)
(d)
(e)
(21)
50.0 L
51.3 L
950 L
990 L
1.02 x 103 L
11.7 L
20.5 L
23.4 L
40.6 L
46.7 L
A gas from a certain volcano was a mixture of CO2 (mole fraction 0.650), H2 (mole
fraction 0.250), HCl (mole fraction 0.054), HF (mole fraction 0.028), and “other
gases.” The total pressure is 760 mm Hg. What is the sum of partial pressures of
the “other gases”?
(a)
(b)
(c)
(d)
(e)
CHE 106
13.7 mm Hg
18 mm Hg
21.3 mm Hg
137 mm Hg
152 mm Hg
5
Fall 2004 Exam #3
(22)
A flask of volume 200.0 mL contains 1.03 mg O2 and 0.56 mg He at 15°C.
Calculate the total pressure. Molar masses: O2, 32.0 g/mol; He, 4.00 g/mol.
(a)
(b)
(c)
(d)
(e)
CHE 106
0.00380 atm
0.0102 atm
0.0165 atm
0.0203 atm
0.0406 atm
6
Fall 2004 Exam #3