Download Chapter (3) Model-A

Chem 110, Final Exam
Time : 90 min
2009 - 1st term
Model (A)
Name:
Useful information:
N A  6.02  10 23 mol 1
Number:
C  3  10 8 m s 1
R H  2.18  10 18 J
Section:
h  6.63  10 -34 J s
R  0.082 L atm K 1 mol 1
With the best wishes
General Chemistry Team work
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Directions: For each of the following questions, choose the letter that best answers the question
and place it on your answer sheet.
[1] The SI prefix
(A)
(B)
(C)
(D)
giga represents:
10-6
106
103
109
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[2] Which of the following relates the volume of gas to the number of molecules of gas?
(A)
Dalton's law
(B)
Boyle's law
(C)
Charles's law
(D)
Avogadro's hypothesis
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[3] The pressure on a 14.4 L sample of oxygen at 748 mm Hg is increased to 1.72 atm at constant
temperature. What will be the new volume in L?
(A)
8.24
(B)
6.40
(C)
17.5
(D)
12.4
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[4] Fill in the blanks: 3.00 moles of nitrogen gas (N2) have a weight of ---------- g , and occupy volume
of ---------- L at STP.
(A)
84.1 g , 67.2 L
(B)
28.0 g , 67.2 L
(C)
28.0 g , 22.4 L
(D)
84.1 g , 1.00 L
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[5] A mixture of gases contains 21 g of H2 and 21 g of He. Calculate the partial pressure of the H2 gas if
the total pressure is 1.15 atm.
(A)
0.247 atm
(B)
2.314 atm
(C)
1.25 atm
(D)
0.765 atm
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[6] Which of the following is a buffer system?
(A)
HCl / NaCl
(B)
H3PO4 / NaH2PO4
(C)
H2SO4 / Na2CO3
(D)
NH3 / NaOH
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[7] Calculate the pH of a buffer solution that contains 0.82 M benzoic acid (C6H5COOH) and 0.35 M
sodium benzoate (C6H5COONa). [Ka = 6.5  10-5 for benzoic acid]
(A)
2.07
(B)
4.63
(C)
5.19
(D)
3.82
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[8] The general formula CnH2n+2 is for
(A)
Alkanes
(B)
Alkenes
(C)
Alkynes
(D)
Cycloalkanes
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[9] Name the following compound:
(A) 1,2-dibromobenzene
(B) 1,2-dibromhexene
(C) 2,3-bromobenzene
(D) bromo-hexane
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(10) The correct structure for 2,2,3-trimethylpentane is
(A)
*(B)
(C)
(D)
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[11] The following molecule: CH3–O–CH2–CH3 is classified as:
(A)
Ketone
(B)
Carboxylic acid
(C)
Ether
(D)
Alcohol
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[12] Name the following compound:
(A)
2,3-butane
(B)
3-butene
(C)
2-pentyne
(D)
2-bytyne
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[13] Find the percent of oxygen (O) in Fe2O3.
(A) 30.1 %
(B) 3.01 %
(C) 6.99 %
(D) 69.9 %
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[14] In the balanced equation y C2H2 + x O2  z CO2 + v H2O , the coefficient x is
(A) 1
(B) 2
(C) 3
(D) 5
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[15] A compound contains 0.2 gram of hydrogen and 0.8 gram carbon. What is the simplest (empirical)
formula of this compound?
(A) CH
(B) CH2
(C) CH3
(D) CH4
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[16] The number of atoms in 1 x 10-3 gram of lead (Pb) is
(A)
(B)
(207)  (6.03  10 23 )
1  10 3
207
3
(1  10 )  (6.03  10 23 )
(1  10 3 )  (6.03  10 23)
207
6.03  10 23
(D)
(1  10 3 )  207
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[17] How many moles of LiClO3 are in 153 mL of a 1.764 M solution?
(A) 0.269
(B) 0.045
(C) 0.341
(D) 0.407
(C)
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[18] 1.00 mole CH4 reacts with excess Cl2. The actual yield of CCl4 is 38.7 g. What is the percent yield
of CCl4 ?
(Atomic weights: C = 12.01, Cl = 35.45).
CH4 + 4 Cl2  CCl4 + 4 HCl
(A)
(B)
(C)
(D)
59.3%
57.3%
65.9%
62.9%
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[19] A 10.0 mL sample of 16.5 M HF is diluted to a final volume of 250.0 mL. What is the molarity of
the final solution?
(A) 0.63
(B) 0.60
(C) 0.66
(D) 0.57
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[20] A photon has a frequency of 6.0 x 104 Hz. Calculate the energy (in joules) of this photon.
(A) 3.98 ×10-39 J
(B) 3.98 ×1039 J
(C) 3.98 ×10-29 J
(D) 3.98×10 29 J
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[21] Which of the following species has the most unpaired electrons S+, S, or S– ?
(A) S+
(B) S
(C) S–
(D) They all have the same number of unpaired electrons.
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[22] Which of these ground-state atoms is diamagnetic?
(A) As
(B) Ca
(C) Cu
(D) Fe
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[23] Find the element having the set of quantum numbers [n=4, L=1, mL=0, ms=+l/2] for its last electron.
(A) 30Zn
(B) 32Ge
(C) 49In
(D) 56Ba
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[24] The electronegativities of the elements D, E, F and G are 3.8, 3.3, 2.8, and 1.3 respectively.
The greatest polar covalent bond character is
(A) FG
(B) DF
(C) DE
(D) EF
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[25] Which of these molecules has an atom with an expanded octet rule?
(A)
NF3
(B)
AsCl3
(C)
H2O
(D)
PF5
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[26] The Lewis structure for a chlorate ion, ClO3-, should show ____ single bond(s), ____ double
bond(s), and ____ lone pair(s).
(A) 2, 1, 10
(B) 3, 0, 9
(C) 2, 1, 9
(D) 3, 0, 10
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[27] Kp will be equal to Kc if _____.
(A) ∆n = 1
(B) ∆n = 0
(C) RT = 0
(D) ∆n = ∞
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[28] If the equilibrium constant for the reaction: A  B  C  D is K, the Equilibrium constant of the
reaction C  D  A  B should be:
(A) K
(B) 1/K
(C)
1
K
2
(D) K2
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[29] The Kc for the following reaction: CO(g) + 2H2(g)
CH3OH(g) is 15.5 at 500 K.
For a system with the concentrations [CO] = 0.170 M, [H2] = 0.340 M, and [CH3OH] = 0.258 M
one can conclude that:
(A) the system is not at equilibrium and the reaction will proceed to the right
(B) the system is at equilibrium and no change will occur
(C) the system is not at equilibrium and the reaction will proceed to the left
(D) the system is not at equilibrium and no change will occur
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[30] The equilibrium constant for the following reaction: N2(g) + 3H2(g)
2NH3(g) is 70 at 350oC.
A system at equilibrium has [N2] = 0.100 M and [H2] = 0.200 M. What is the [NH3]?
(A) 0.371
(B) 0.195
(C) 0.237
(D) 0.302
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[31] The following reaction is at equilibrium
2SO3(g)
2SO2(g) + O2(g)
If the temperature is increased,
(Hº = +198 kJ/mol)
(A) more SO3 will be produced.
(B) more O2 will be produced.
(C) no change will occur in Kc .
(D) none of these.
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[32] The reaction in which increased pressure has no affect on the equilibrium reaction is
(A) N2(g) + 3 H2(g) ⇄ 2 NH3(g)
(B) 2 H2(g) + CO(g) ⇄ CH3OH(L)
(C) CaCO3(s) ⇄ CaO(s) + CO2(g)
(D) CO(g) + H2O(g) ⇄ CO2(g) + H2(g)
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[33] Indicate the type of hybrid orbitals used by the arsenic atom in AsCl3
(A) sp
(B) sp2
(C) sp3
(D) None of these
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[34] Name the following molecular compound: P4O10
(A) Tetraphosphorus decoxide
(B) Decaphosphorus pentoxide
(C) Phosphorus decaoxide
(D) Tetraphosphorus pentaoxide
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[35] What is the formula of chromium (III) sulfide?
(A) CrS3
(B) Cr2S3
(C) Cr3S2
(D) Cr3S
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[36] In what group of the periodic table is the element with the electron configuration
[Ar]4s23d104p3?
(A) 1A
(B) 2A
(C) 3A
(D) 5A
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[37] Which of these elements has the highest ionization energy?
(A) Cs
(B) Ga
(C) K
(D) As
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[38] If the pOH of a solution is 7, the solution will be:
(A) Acidic
(B) Alkaline
(C) Neutral
(D) Non of these
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[39] The hydroxide ion (OH-) concentration of lemon juice is about 2.0 x 10-12. The pH of lemon
juce is:
(A) pH = 2.3
(B) pH = 12
(C) pH = 9.0
(D) pH = 4.1
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[40] A protein is
(A)
(B)
(C)
(D)
a polymer of ester.
a polymer of amino acids.
an aromatic hydrocarbon.
None of these.
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