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Principles of Chemistry I
3150:151-005
EXAM I
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Number and Test Form below:
Monday, 12:05 PM
TEST 1, FORM A
September 19, 2011
140 pts.
Instructions:
1.
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2.
Enter your name on this page and on your computer answer sheet.
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CODE your name (LAST NAME FIRST), ID number (with two leading zeros), and the indicated
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4.
Put all calculations on the examination pages or scratch paper. Do not make any extra marks on the
computer answer sheet!!
5.
This exam consists of 28 multiple-choice questions worth 5 points each. For each multiple-choice
question, choose the ONE best or correct answer and write it both on your exam paper and on the
answer sheet. The computer answer sheet is the only one that will be graded!
6.
This exam booklet consists of 6 pages (including this one), a Periodic Table/Formula Sheet, and a
sheet of blank paper. Please check to be sure that you have them all!
7.
Unless otherwise stated in a question, solutions are aqueous and substances are at 25 °C and 1 atm
(~100 kPa).
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The Management
_____ 1.
What is the name of this compound? P 4 S 3
(A) phosphorus sulfide
(B) phosphorus trisulfide
(C) phosphorus(IV) sulfide
(D) tetraphosphorus trisulfide
(E) phosphorus(IV) sulfide(III)
_____ 2.
The formula for the ionic compound sodium vanadate is Na 3 VO 4 . What is the formula for
calcium vanadate?
(A) Ca 3 VO 4
(B) Ca 2 VO 4
(C) Ca 3 (VO 4 ) 2
(D) Ca 2 (VO 4 ) 3
(E) CaVO 4
_____ 3.
What is the formula of copper(II) sulfate pentahydrate?
(A) Co 2 SO 4 •5H 2 O
(B) CoSO 4 •5H 2 O
(C) Cu 2 SO 4 •5H 2 O
(D) CuSO 4 •5H 2 O
(E) CuSO 4 •H 10 O 5
_____ 4.
Which quantity contains the most atoms?
(A) 2.0 g H 2
(B) 4.0 g He
(C) 8.0 g O 3
(D) 14 g N 2
_____ 5.
2.01 g of hydrogen combine with 70.90 g of chlorine to form 72.91 g of hydrogen chloride with
no hydrogen or chlorine left over. How many grams of hydrogen chloride are formed when
6.03 g of hydrogen react with 250.0 g of chlorine, and how much of which element will be left
over?
(A) 218.7 g of hydrogen chloride formed; 37.3 g of chlorine left over
(B) 212.7 g of hydrogen chloride formed; 37.3 g of chlorine left over
(C) 212.7 g of hydrogen chloride formed; 43.3 g of chlorine left over
(D) 218.7 g of hydrogen chloride formed; 4.02 g of hydrogen left over
(E) It’s impossible to tell with the information provided.
_____ 6.
2.00 liters of a solution contain 147 g of H 2 SO 4 . What is the molarity of the solution?
(A) 0.750 M
(B) 1.50 M
(C) 2.25 M
(D) 2.94 M
(E) 3.00 M
_____ 7.
Molar Mass/g·mol–1
H2SO4
98.09
Which contains 21 neutrons?
21
(A) 10
Ne
(B)
45
21
Sc3+
(C)
52
24
Cr 3+
(D)
40
19
K
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_____ 8.
What is the coefficient for H 2 O when the equation is balanced with the smallest whole
numbers?
___ Al 4 C 3 (s) + ___ H 2 O (l) → ___ CH 4 (g) + ___ Al(OH) 3 (s)
(A) 1
(B) 3
(C) 4
(D) 6
(E) 12
_____ 9.
Which would most likely result in calculating a reaction percent yield that is over 100%?
(A) splattering of the reactants as they are heated.
(B) spilling some of the products on the benchtop before weighing.
(C) weighing the product sample while wet.
(D) random errors in the analytical balance.
_____ 10.
Which temperature is the hottest?
(A) 451 °F
(B) 451 °C
(C) 451 K
(D) all of these are the same.
(E) the temperatures can not be compared since they have different units.
_____ 11.
Atoms of different elements have different chemical properties because atoms of different
elements have different numbers of
(A) electrons.
(B) neutrons.
(C) protons.
(D) alpha particles.
(E) quarks.
_____ 12.
Two objects have the same mass, but one has more volume than (is larger than) the other.
Which object has the smaller density?
(A) the larger object
(B) the smaller object
(C) both objects have the same density.
(D) it is impossible to tell without additional information.
_____ 13.
When 12.0 g of H 2 reacts with 12.0 g of Cl 2 , 5.53 g of HCl were
recovered. What was the percent yield?
H 2 (g) + Cl 2 (g) → 2 HCl(g)
(A) 1.27%
(B) 2.55%
(C) 45.0%
(D) 89.9%
(E) 100%
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Molar Mass/g·mol–1
H2
2.016
Cl2
70.90
HCl
36.46
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_____ 14.
Which is symbolized by the diagram?
36e–
35p+
45no
(A) 4535 Br
(B) 4535 Br −
(C) 8035 Br
(D) 8035 Br −
(E) 8036 Kr
_____ 15.
Which diagram represents a microscopic view of a gaseous mixture of two elements?
_____ 16.
A 1.587 g sample of a compound containing only sulfur and chlorine is analyzed and found to
contain 0.754 g S. What is the empirical formula of the compound?
(A) SCl
(B) SCl 1.10
(C) S 2 Cl 2
(D) S 2 Cl
(E) SCl 2
_____ 17.
Naturally occurring 37 Rb contains two isotopes, 85Rb and 87Rb. The abundance of 85Rb is
(A) less than 5%.
(B) between 5% and 45%.
(C) between 45% and 55%.
(D) between 55% and 95%.
(E) more than 95%.
_____ 18.
A student prepares 500.0 mL of 0.100 M NaOH in a volumetric flask but then spills 25 mL of
the solution on the bench top. What is the concentration of the solution remaining in the flask?
(A) 0.0952 M
(B) 0.100 M
(C) 0.105 M
(D) 50.0 M
(E) none of the above
_____ 19.
A student neutralized 10.00 mL of citric acid (H 3 C 6 H 5 O 7 ) solution with 22.53 mL of 0.1157 M
sodium hydroxide solution. What was the concentration of the citric acid solution?
H 3 C 6 H 5 O 7 (aq) + 3 NaOH (aq) → Na 3 C 6 H 5 O 7 (aq) + 3 H 2 O (l)
(A) 0.01712 M
(B) 0.05135 M
(C) 0.08689 M
(D) 0.2607 M
(E) 0.7820 M
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_____ 20.
Consider these reactions and experimental % yields. What is the % yield of reaction 3?
(1) X + Z → J
(2) J + Z → M
(3) X + 2Z → M
yield = 70.0%
yield = 90.0%
yield = ????%
(A) 20.0%
(B) 63.0%
(C) 70.0%
(D) 80.0%
_____ 21.
Cortisol is one of the major steroid hormones used in the treatment of rheumatoid arthritis.
Cortisol is 69.6% C, 8.34% H, and 22.1% O by mass. If the molar mass of cortisol is
362.47 g·mol–1, how many oxygen atoms are in the molecular formula for cortisol?
(A) 1
(B) 5
(C) 10
(D) 15
(E) 21
_____ 22.
How many grams of nitrogen gas can be formed when 100.0 grams
of hydrazine and 200.0 grams of N 2 O 4 react?
2 N 2 H 4 (l) + N 2 O 4 (l) → 3 N 2 (g) + 4 H 2 O (l)
(A) 662 g
(B) 331 g
(C) 183 g
(D) 131 g
(E) 31 g
_____ 23.
Molar Mass/g·mol–1
N2
28.02
32.05
N2H4
N2O4
92.02
Calculate the percent by mass of lead in the mineral vanadinite, which has the formula
Pb 5 (VO 4 ) 3 Cl.
(A) 2.50 %
(B) 10.79 %
(C) 13.56 %
(D) 57.14 %
(E) 73.15 %
_____ 24.
Which is an empirical formula?
(A) P 4 O 6
(B) PCl 3
(C) both (A) and (B)
(D) neither (A) nor (B)
_____ 25.
Which does NOT show an ion commonly found in compounds?
(A) Na+
(B) Cl−
(C) S2−
(D) K−
(E) Cu2+
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_____ 26.
Which element does NOT exist in its most stable form as diatomic molecules?
(A) nitrogen
(B) hydrogen
(C) carbon
(D) fluorine
(E) oxygen
_____ 27.
How many grams of CaCl 2 are needed to make 50.0 mL of a 3.00 M solution?
(A) 5.55 g
(B) 11.1 g
(C) 16.6 g
(D) 1.85 × 103 g
(E) 1.66 × 104 g
_____ 28.
Molar Mass/g·mol–1
CaCl2
110.98
How many milliliters of 3.0 M CaCl 2 are needed to make 500.0 mL of a 0.66 M solution?
(A) 0.11 mL
(B) 110 mL
(C) 330 mL
(D) 990 mL
(E) 2300 mL
End of Exam
Check to see that you have entered 28 answers on your scan sheet. Proofread your work.
When leaving the room, you must turn in your scan sheet. You can keep this exam booklet.
Answers will be posted on the course web site (hopefully later today).
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