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CHM134: General Chemistry I
Final Exam: Spring 2009
Name___________________________________
Please circle all final answers. For full credit you must report all responses to the correct number of significant
figures. Include units and substances where appropriate. You may use only the basic arithmetic functions of
your calculator.
1. 4 pts. Classify each of the following as an element, a compound, a heterogeneous mixture, or a homogeneous
mixture:
human blood
chlorine gas
beef stew
apple juice
Iron will rust. Is this a physical or chemical property?
2.
1 pt.
3.
4 pts.
How many significant figures are in the following numbers?
3.407 x 102 pm
4.
5.
4 pts.
___
50 g
___
122 cm
___
0.00104 m
___
Perform the following calculations to the correct number of significant figures:
2.5 + 12.456 + 124.78 = ______
45.6 x 3.211 = ______
(37.53 – 33.21) / 2.682 = ______
(37.3 / 2.5) + 96.4 = ______
The width of my desk is 238 cm. How many inches wide is this? _____________
1 pts.
6. 2 pts. A pool measures 45.0 meters long, 60.0 meters wide, and is 4.00 meters deep. How many liters of water
can the pool contain? You must show your work:
7. 2 pts. What is the volume in mL of an object that has a density of 17.7 g/mL and a mass of 287 mg?
8.
1 pt
9.
3 pts.
10.
Write the isotopic symbol for a phosphorus isotope that has 16 neutrons: _________
The atomic ion 50Sr2+ atom has ___ protons, ___ neutrons, and ___ electrons.
3 pts.
Give an example of an alkali metal _____, a halogen _____, and a metalloid _____
11.
2 pts.
Calculate the atomic mass of Rb using the following data. (Show work in table)
Isotope Isotope Mass [amu] Natural Abundance
Rb-85
84.9118
72.15 %
Rb-87
86.9092
27.85 %
Atomic mass =
12.
2 pts.
How many actual lead atoms (not moles) are in a block that has mass 62.7 grams?
13.
2 pts.
How many actual hydrogen atoms (not moles) are in 23.8 grams of water?
14.
2 pts.
Calculate the mass percent of Na present in the compound NaClO2
15.
2 pts.
What is the empirical formula of a compound that is 75.92 % C, 6.37 % H, and 17.70 % N by mass?
16.
4 pts.
Provide a name for each of the following:
Na2O
LiNO3
N2Cl4
H2O2
Co(OH)2
FeS
AlCl3
Mg3(PO3)2
17.
4 pts.
Provide a formula for each of these names:
calcium bromide
nickel (II) sulfide
sodium chlorate
dinitrogen pentachloride
nitric acid
carbon dioxide
magnesium oxide
ammonium chloride
18. 2 pts. Balance the following chemical equations:
__ CH4 + __ O2 Æ __ CO2 + __ H2O
__ C12H22O11 + __ H2O Æ __ C2H6O + __ CO2
19. 5 pts. Circle the compounds that will not dissolve in water:
RbI
CaF
PbBr2
KOH
Na2CO3
CuSO4
Mg3(PO4)2
(NH4)2S
K2SO4
Co(NO3)2
20. 6 pts. Consider the following reaction:
2 Mg(s) + CO2 (s) Æ C(s) + 2 MgO (s)
a. If 34 grams of Mg completely react with an excess amount of carbon dioxide, how many grams of solid
carbon will be produced?
b. How much of the carbon dioxide would be needed to react with the 34 grams of Mg?
21.
6 pts.
Consider the following chemical reaction:
2 Al (s) + 3 H2SO4 (aq) Æ Al2(SO4)3 (aq) + 3 H2 (g)
a. If 15.6 grams of Al are added to 90.0 mL of a 1.00 M H2SO4 solution, what is the maximum number of
grams of H2 that can form?
b. How many grams of each reactant would be left?
22. 2 pts. Explain how you would prepare 100.0 mL of a 0.2500M CaCl2 solution using the solid, volumetric
glassware, and water. Be specific in terms of how you would do it.
23. 2 pts. Explain how you would prepare 500.0 mL of a 2.000M HNO3 solution by using a stock solution of
12.00M HNO3 solution, volumetric glassware, and water. Be specific.
24. 4 pts. Complete and balance each of the following molecular equations.
NH4I (aq) +
CuSO4 (aq) +
HCl (aq) +
Pb(NO3)2 (aq) Æ
Ba(NO3)2 (aq) Æ
Na2CO3 (aq) Æ
H2SO4 (aq) + KOH (aq) Æ
25.
4 pts.
Assign oxidation numbers to the underlined atom in each case:
H3PO4 ____
H2O2 ____
O2 ____
HClO4 ____
NaOH ____
CaCl2 ____
C2H4 ____
NaH ____
26. 5 pts. Identify the oxidizing agent, the reducing agent, the element being oxidized, the element being reduced,
and the number of electrons transferred in this balanced chemical equation:
4 HNO3 + 3 S Æ 3 SO2 + 4 NO + 2 H2O
oxidizing agent ______________________
atom being oxidized _____
reducing agent ______________________
atom being reduced _____
# of electrons transferred in the balanced equation _____
c = 2.998 x 108 m/s
h = 6.626 x 10-34 J.s
27.
2 pts. How long will it take light to travel from Earth to Jupiter when the red planet is at its most distant
point (9.64 x 108 km away)?
28.
1 pt
Circle the type of electromagnetic radiation that has the shortest wavelength:
red light
microwaves
ultraviolet light
29.
2 pts.
30.
2 pts. A laser pulse with wavelength equal to 515 nm contains 1.24 mJ of energy. How many photons are in
the laser pulse?
31.
1 pt
Calculate the frequency of light [in Hz] associated with indigo light (wavelength equal to 435 nm).
Circle the one combination of quantum numbers that would not be allowed:
(n=1 l=2 ml=2)
32.
(n=1 l=0 ml=0)
(n=3 l=1 ml=-1)
Calculate the wavelength of light (in nm) emitted when a hydrogen atom drops from an n=4 to an n=1
level. The energy of a hydrogen atom is (-2.18 x 10-18 J) / n2
2 pts.
33.
3 pts.
Write complete (no abbreviations) electron configurations for each of the following:
2 pts.
Write electron configurations for each of the following (you may abbreviate):
O
Al
Cr
34.
Zr2+
Rn
35.
1 pt
Circle the atom with the larger atomic radius:
Al
Cl
36.
1 pt
Circle the atom with the larger atomic radius:
Ca
Ba
37.
1 pt
Circle the atom with the greater 1st ionization energy:
Rb
Sr
38.
1 pt
Circle the atom with the greater 1st ionization energy:
Be
B
39.
1 pt
Circle the atom with the greater 1st ionization energy:
F
I
40.
1 pt
Circle the atom with the greater (more negative) electron affinity: N
O
41.
1 pt
Circle the atom with the greater (more negative) electron affinity: Si
Cl
42.
1 pt
Circle the atom with the greater electronegativity:
43.
2 pts.
N
F
Assign formal charges to the non-hydrogen atoms of this Lewis Structure:
+
N
C
H
44.
1 pt.
Is PF5 a polar molecule? YES or NO
45.
1 pt.
Is PF3 a polar molecule? YES or NO
O
Cl
46.
2 pts.
Write Lewis Dot structures for each of the following:
H2NNH2
CH4
47. 2 pts. Write Lewis Dot structures for these. If possible, expand the octet to produce better formal charges. If
appropriate, draw all resonance forms.
NO3-
SF4
48. 4 pts. Complete the Lewis Structure for this molecule whose empirical formula is C4H9ON. The octet rule
must be obeyed for all non-hydrogen atoms!
H
H
H
O
H
H
H
C
C
C
C
N
H
H
H
49. 6 pts. Draw a VSEPR sketch (with approximate angles) for each of these. Give the name of the molecular
geometry and the hybridization in each case:
XeF2
SO2
geometry ______________________
geometry ______________________
hybridization ___________
hybridization ___________