Chm 101
Final Exam 200 Points
12-12-12
Name
Multiple Choice: circle the one best answer (4 pts. each)
1) What type of bond results from the sharing of two or more valence electrons between one atom and
another?
a) valence bond
b) ionic bond
c) nonmetallic bond
d) covalent bond
e) none of the above
2) Which of the following is an example of a polyatomic anion?
a) Cl-
b) Na+
c) NH4+
d) NO3-
d) Ca
3) Which of the following elements is the most electronegative?
a) cesium
b) hydrogen
c) radon
d) fluorine
e) arsenic
4) Which of the following contains a “non-polar” covalent bond?
a) N2
b) NaCl
c) SO42-
d) H2O
5) The percent ionic character in a single O-H bond is approximately:
a) 10%
b) 25%
c) 35%
d) 100%
e) both c and d
6) Which of the following contains ionic bonding?
a) CO
b) SrF2
c) Al
d) OCl2
7) Which of the following elements is classified as a metalloid?
a) Mg
b) S
c) As
d) Pb
8) According to Coulomb’s Law, the lattice energy for ionic crystals increases as the charge on the ions
_____________ and the size of the ions __________________ .
a) increases, decreases
b) decreases, increases
c) decreases, decreases
d) increases, increases
9) Which of the following compounds would you expect to have the greatest lattice energy?
a) CaS (s)
b) MgO (s)
c) NaI (s)
d) LiBr (s)
10) Which of the following atoms has the largest first ionization energy?
a) Cs
b) Mg
c) F
d) Co
e) all the same
11) Which of the following would you expect to have the longest bond length?
a) C≡C
b) N≡N
c) C=C
d) C-C
12) The vertical columns of the periodic table are called:
a) periods
b) metals
c) main group elements
d) allotropes
e) groups or families
13) Measurement has often been called the fundamental science. Which of the following quantities can be
measured exactly?
a) length
b) mass
c) volume
d) time
e) none of the above
14) The SI prefixes kilo- and micro- represent respectively (order as listed):
a) 106 and 10-6
b) 10-3 and 10-6
c) 103 and 10-6
d) 10-3 and 109
15) The bond length in a molecule of HCl is 0.000 000 000 127 meters. This distance, expressed in
standard scientific notation is:
a) 1.27 x 10-11 m
b) 1.27 x 10-10 m
c) 1.27 x 10-9 m
d) 1.27 x 1010 m
16) A student reported the results of a mass measurement as 0.02010 g. How many significant figures
does this measurement contain?
a) 1
b) 2
c) 3
d) 4
e) 5
17) Atoms of the same element with different atomic mass numbers are called:
a) nucleons
b) neutrons
c) allotropes
d) chemical families
e) isotopes
18) What is the term that expresses the smallest whole number ratio of atoms in a molecule?
a) chemical formula
b) empirical formula
c) molecular formula
d) mass ratio composition
e) percent composition
19) The number of protons (p), neutrons (n), and electrons (e) in the isotope 206Pb is:
a) 206 p, 124 n, 82 e
b) 206 p, 124 n, 206 e
c) 82 p, 206 n, 82e
d) 82 p, 124 n, 82 e
20) Which of the following is the reference isotope for the atomic mass (amu) scale?
a) 1H
b) 2H
12
c)
C
d)
14
N
e)
13
C
21) Which subatomic particle accounts for the charge on an atom’s nucleus?
a) electron
b) neutron
c) proton
d) photon
22) The boiling point of oxygen is 90 K. What is this temperature expressed in degrees Celsius (oC)?
a) -183 oC
b) 196 oC
c) -196 oC
d) -77 oC
e) -363 oC
23) The molarity of a solution prepared by diluting 50.00 mL of 12.1 M HCl to a volume of 150.00 mL is:
a) 4.03 M
b) 49.1 M
c) 0.037 M
d) 8.10 M
24) The oxidation number of chromium in K2Cr2O7 is:
a) +2
b) -7
c) -6
d) +3
e) none of the above
For any of the following problems involving calculations, you must show all of your work to receive
full credit! Watch Significant figures.
25) Write the complete ground state electron configuration for the S2+ ion. (4 pts.)
26) Use the symbols  + and - to indicate the polarity of the following single bonds. (4 pts.)
C-H
O-H
C-O
S-N
27) The following are all legitimate Lewis dot structures for the perchlorate ion, ClO4-. Select the “best”
structure based on formal charge considerations. (9 pts.)
1-
O
O
Cl
O
O
O
Cl
O
Cl
O
O
1-
O
O
1-
O
O
1-
O
O
Cl
O
O
28) Draw the Lewis dot structures for two of the resonance forms of the NO2- ion. (6 pts.)
29) The ability of molecules to absorb radiation of various frequencies depends in large part on the
structure of the molecule and the location of the electrons. Write Lewis dot structures for the
following important greenhouse gasses. (4 pts. each)
H2O
CO2
30) Write Lewis dot structures for the following molecules or ions. Identify those that do not obey the
octet rule and state why e.g. too few electrons, expanded octet, etc.. (3 pts. each)
NH4+
BH3
HCN
SF6
31) Chemical reactions proceed spontaneously in large part because weaker bonds are replaced by stronger
bonds. Use Lewis Structures and average bond enthalpies to estimate the enthalpy change for the
following reaction. Hint: Make sure the equation is balanced before you do your calculation. (9 pts.)
HCN (g) +
H2 (g) 
CH3NH2 (g)
32) Calculate the molar mass (molecular weight) of the explosive compound nitroglycerin, C3H5(NO3)3 .
(6 pts.)
33) Ethanol, C2H5OH, is often added to gasoline in order to reduce pollution. Write a balanced equation for
the complete combustion of ethanol and indicate whether the reaction is endothermic or exothermic.
(8 pts.)
34) A solution of 100.0 mL of 0.300 M AgNO3 (aq) is mixed with 150.0 mL of 0.200 M CaCl2 (aq).
a) Write a complete ionic equation for the reaction. (3 pts.)
b) Write a net ionic equation for the reaction. (3 pts.)
c) Identify the limiting reactant, if any. (4 pts.)
d) Calculate the mass of precipitate, if any, that forms. (4 pts.)
35) Calculate the amount of heat that is lost by 4.50 mols of water as it cools from 90.0 oC to
10.0 oC. (8 pts.)
36) An AM radio station broadcasts at 1440 kHz, and its FM partner broadcasts at 94.5 MHz. Calculate the
energy of the photons emitted by these two radio stations. (8 pts.)
37) Use up and down arrows (  ) to show the ground state electron occupancy of the nitride ion, N3ion on the energy diagram below. ( 8 pts.)
3s
3p
Energy
2s
2p
1s
Extra Credit: Choose One (10 pts., all or none)
1) A package of aluminum foil contains 50.0 ft2 of foil, which weighs 8.0 ounces (oz.). What is the
thickness of the foil in millimeters?
2) A person suffering from hyponatremia has a sodium ion concentration in the blood of 0.118 M and a
total blood volume of 4.6 L. What mass of sodium chloride would need to be added to the blood to
bring the sodium ion concentration up to 0.138 M, assuming no change in blood volume?
Potentially Useful Information
1 mile ≡ 5280 feet
c = 
1 foot ≡ 12 inches
E = hhc/
2.54 cm ≡ 1 inch
E = q + w
1 ounce (oz) = 28.35 g
q = m C T
1 pound (lb)  16 oz
1 cal ≡ 4.184 J
1 quart (qt) = 0.9463 L
1 J = 1 kg m2 / s2
Specific Heat of water = 4.184 J/g oC
KE = ½ mv2
Speed of Light
c = 3.00 x 108 m/s
H = E + PV
Planck’s Constant h = 6.63 x 10-34 Js

E = x 10-18 J)(1/n2f – 1/n2i)
Rydberg Equation
1

1
= RH
ni2
 =
h
mv
- 12
nf
RH = 1.09678 x 107 m-1
De Broglie wavelength
Horxn =  n Hof (products) -  n Hof (reactants)
R = 0.0821 L atm / mol K = 8.314 J/mol K
1 atm ≡ 760 torr ≡ 760 mm Hg = 14.7 lbs/in2
Average Bond Enthalpies (kJ/mol)
C-C
C=C
C-H
C-N
C≡N
N-H
H-H
348
614
413
293
891
391
436
O-O
O=O
N-O
N=O
C=O
C-O
O-H
146
495
201
607
799
358
463