Chem 1025 Final Exam
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1
2Form Code A
CHEM 1025 Final Exam
28 Apr. 2010
Instructions: On your scantron sheet enter your name, UF ID number, and Form Code (start with the first space and leave
the last space blank). This exam consists of 25 multiple choice questions each worth 8.0 points for a total maximum of
200 pts. Keep your exam sheet (mark your answers on it and on the scantron sheet). Turn in only the scantron. Any
bubbling error will count as an incorrect response, including wrong form code and answers.
Potentially Useful Information: 1 inch = 2.54 cm; 12 inches = 1 foot; 1 mile = 5280 ft
1. Compound X has three isotopes: X-28, X-29, and X-30. X-28 has a mass of 27.9769 amu and is 68.3% abundant. X-
29 has a mass of 28.9765 amu and is 19.2% abundant. X-30 has a mass of 29.9737 amu is 12.5% abundant. Calculate
the atomic mass of compound X.
(1) 28.4184 amu
(2) 28.4 amu
(3) 28.4184232 amu
(4) 28.42 amu
(5) 28.418 amu
2. Name the following compounds: CrCl
, Fe(NO
)
, N
O
.
4
3
2
2
2
(1) Chromium (II) chloride, iron (II) nitrite, dinitrogen dioxide
(2) Chromium (II) quatrachloride, iron nitrate, nitrogen (II) oxide
(3) Chromium (IV) chloride, iron (II) nitrate, dinitrogen dioxide
(4) Chromium tetrachloride, iron (II) nitride, nitrogen (II) dioxide
(5) Chromium (IV) chlorine, iron nitrite, nitrogen dioxide
3. How many atoms of phosphorous are there in 2.0 g of P
S
.
4
10
25
24
22
23
22
(1) 1.9 x 10
(2) 2.5 x 10
(3) 4.3 x 10
(4) 1.1 x 10
(5) 1.1 x 10
4. Perform the following calculation to the correct number of significant figure.
6
5
[(2.3 x 10
) ÷ (9.63 x 10
)] + 9.76
(1) 13.8
(2) 12.15
(3) 14
(4) 12.1
(5) 13
3
5. A pure titanium cube has an edge length of 0.973 ft. How many titanium atoms does it contain? (D
= 4.50 g/cm
).
Ti
24
25
27
(1) 1.22 x 10
atoms
(2) 2.00 x 10
atoms
(3) 1.48 x 10
atoms
22
(4) 5.21x 10
atoms
(5) Insufficient information
6. What volume (in mL) of 0.500 M NaOH is required to titrate 150.00 mL of 1.10 M H
SO
to the equivalence point?
2
4
(1) 660. mL
(2) 12.5 mL
(3) 25.0 mL
(4) 330. mL
(5) 1320 mL
7. Name of the compound (NH
)
CrO
4
2
4
(1) Ammonia chromate oxide
(2) Ammonium chromate
(3) Ammonium dichromate
(4) Ammonia chromate
(5) Ammonia dichromate
8. What is the complete ionic equation for the following balanced reaction:
NH
Cl(aq) + NaOH(aq) → H
O(l) + NH
(g) + NaCl(aq)
4
2
3
+
-
(1) H
(aq) + OH
(aq) → H
O(l)
2
+
-
(2) NH
(aq) + OH
(aq) → H
O(l) + NH
(g)
4
2
3
+
-
+
-
+
-
(3) NH
(aq) + Cl
(aq) + Na
(aq) + OH
(aq) → H
O(l) + NH
(g) + Na
(aq) + Cl
(aq)
4
2
3
(4) No Reaction
+
-
+
-
+
-
(5) NH
(aq) + Cl
(aq) + Na
(aq) + OH
(aq) → Na
(aq) + Cl
(aq)
4
9. The following reaction is used to obtain iron from iron ore:
Fe
O
(s) + 3CO(g) → 2Fe(s) + 3CO
(g)
2
3
2
The reaction of 92.134 g Fe
O
with 143.21 g CO produces 2.45 g Fe. Determine the percent yield.
2
3
(1) 3.80%
(2) 7.60%
(3) 1.29%
(4) 4.21%
(5) 63.4%
10. Calculate the molecular formula for nicotine based on its elemental mass percent composition (C 51.28%, H 9.40%,
O 27.35%, and N 11.97%) and its molar mass (~234 g/mol).
(1) C
H
N
(2) C
H
O
N
(3) C
H
O
N
(4) C
H
O
N
(5) C
H
O
N
10
14
2
5
11
2
8
16
4
4
10
22
4
2
12
16
2
3
11. If a system emits 200 kJ of energy during a process, what is the change in energy for the surroundings (∆E
)? Is this
surr
process endo- or exothermic for the system?
(1) +200 kJ; endothermic
(2) +200 kJ; exothermic
(3) -200 kJ; endothermic
(4) -200 kJ; exothermic
(5) Not enough information
12. Use Hess’ Law and the following data to determine the value of ΔH
for the following reaction:
rxn
5 C(s) + 6 H
(g) C
H
(l)
2
5
12
(g) 5 CO
C
H
(l) + 8 O
(g) + 6 H
O(g)
ΔH
= -3505.8 kJ
5
12
2
2
2
1
C(s) + O
(g) CO
(g)
ΔH
= -393.5 kJ
2
2
2
2 H
(g) + O
(g) 2 H
O(g)
ΔH
= -483.5 kJ
2
2
2
3
(1) 4382.8 kJ
(2) 87.8 kJ
(3) -4382.8 kJ
(4) -2628.8 kJ
(5) -2988.8 kJ
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