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9AM
CHEM 1A – B.Kunkel
Practice Final Exam
F2014
There are a total of 50 questions on the exam (there are 54 questions on the practice exam). Each
question is worth 4 points. You must show your work on the exam. We can evaluate your exam only if
you have shown work.
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________________________________________________________________________________
1. An element's most stable ion forms an ionic compound with fluorine having the formula XF 3. If the
X ion has 24 electrons, which of the following is element X?
A) Sc
B) Co
C) Cr
D) V
E) none of the above
2. A sample of HOOCC6H4OH contains 0.6540 moles of hydrogen atoms. How many moles of carbon
atoms are in the sample?
A)
B)
C)
D)
E)
0.6543 moles
6.090 moles
7.015 moles
1.290 moles
0.7630 moles
3. How many oxygen atoms are in 2.74 grams of aluminum sulfate?
A) 6.02 x 1023
B) 7.22 x 1024
C) 5.79 x 1022
D) 8.01 x 10-3
E) none of the above
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9AM
CHEM 1A – B.Kunkel
Practice Final Exam
F2014
4. Combustion of a 1.031 g sample of a compound that only contains carbon, hydrogen and oxygen
produces 2.265 g of CO2 and 1.236 g of H2O. What is the empirical formula of the compound?
A) C3H8O
B) C3H5O
C) C3H6O3
D) C3H9O3
E) none of the above
5. How many grams of water are produced from the complete combustion of 24.42 g of C4H10O?
A) 18.00 g
B) 24.00 g
C) 30.00 g
D) 36.00 g
E) none of the above
6. A salt (ionic compound) contains only barium and one of the halogens. A 0.1480 g sample of the salt
was dissolved in water and an excess of sulfuric acid was added to form barium sulfate, a solid. The
barium sulfate was filtered, dried and weighed and its mass was found to be 0.1660 g. Which halogen is
in the salt?
A) fluorine
B) chlorine
C) bromine
D) iodine
E) none of the above
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9AM
CHEM 1A – B.Kunkel
Practice Final Exam
F2014
7. What is the mass, in grams, of a magnesium sample which contains 3.22 × 1022 magnesium atoms?
A)
B)
C)
D)
E)
12.2 g
1.30 g
7.50 × 10-4 g
5.88 g
none of the above
8. Which set below contains ONLY weak electrolytes?
A)
B)
C)
D)
E)
HNO3(aq), H2SO4(aq), HCN(aq)
KOH(aq), H3PO4(aq), NaClO4(aq)
NH3(aq), HC2H3O2(aq), HCN(aq)
NH4Cl(aq), HClO2(aq), HCN(aq)
more than one of the above contains ONLY weak electrolytes
9. A compound has an empirical formula of CH2O. An independent analysis gave a value of
150.13 g/mol for its molar mass. What is the molecular formula of the compound?
A)
B)
C)
D)
E)
C5H10O5
C6H12O6
C11H2O
C6H6O8
none of the above
10. What volume of 3.25 M (NH4)2SO4(aq) is needed in order to give 8.60 g of (NH4)2SO4?
A)
B)
C)
D)
E)
2.65 mL
20.0 mL
50.0 mL
212 mL
none of the above
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9AM
CHEM 1A – B.Kunkel
Practice Final Exam
F2014
11. When aluminum metal reacts with HCl(aq), the products formed are AlCl3(aq) and hydrogen gas.
If 0.159 moles of aluminum undergo this reaction with an excess of hydrochloric acid, how many
grams of hydrogen gas should be produced?
A)
B)
C)
D)
E)
0.318 grams
0.477 grams
6.048 grams
0.212 grams
none of the above
12. The following compounds are put into water:
I. silver chloride, AgCl
II. silver nitrate, AgNO3
III. sucrose, C12H22O11
IV. calcium chloride, CaCl2
V. ammonium bromide, NH4Br
which of these conduct electricity well?
A)
B)
C)
D)
E)
I and V, only
III, IV and V, only
I and IV, only
I, IV and V, only
II, IV and V, only
13. You are given the following UNBALANCED chemical equation:
C4H8 + O2  CO2 + H2O.
If 0.3218 moles of C4H8 are allowed to react with 1.238 moles of O2, what would be the theoretical yield
of water, in grams?
A)
B)
C)
D)
E)
23.11 g
5.792 g
36.03 g
14.86 g
none of the above
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9AM
Practice Final Exam
CHEM 1A – B.Kunkel
14. Which of the following involves reduction?
F2014
A) Ca2+(aq) + CO32(aq)  CaCO3(s)
B) 2 H+(aq) + SO32(aq)  H2O(l) + SO2(g)
C) VO43(aq)  VO2+(aq)
D) CrO2 (aq)  CrO42(aq)
E) none of the above
15. Which is the net ionic equation for the reaction which takes place when HC 2H3O2(aq) is added to
NaOH(aq)?
A) HC2H3O2(aq) + NaOH(aq)  NaC2H3O2 (aq) + H2O(l)
B) H+(aq) + OH(aq)  H2O(l)
C) HC2H3O2(aq) + OH(aq)  C2H3O2(aq) + H2O(l)
D) H+(aq) + NaOH(aq)  Na+(aq) + H2O(l)
E) HC2H3O2(aq) + Na+(aq)  NaC2H3O2 (aq) + H+(aq)
16. How many grams of the excess reagent are left over when 6.00 g of CS 2 gas react with
10.0 g of Cl2 gas in the following reaction:
CS2 (g) + 3 Cl2 (g) → CCl4 (l) + S2Cl2 (l)
A) 4.00 g
B) 2.77 g
C) 3.58 g
D) 2.42 g
E) none of the above
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9AM
CHEM 1A – B.Kunkel
Practice Final Exam
F2014
17. If 25.0 mL of 0.145 M H2SO4 (aq) is required to completely neutralize 54.1 mL of a NaOH
solution. What is the molarity of the NaOH solution?
A)
B)
C)
D)
E)
2.52 M
0.134 M
0.067 M
1.67 M
none of the above
18. Iron reacts with hydrochloric acid according to the following reaction. What volume of
1.80 M HCl(aq) will react with 55.1 g Fe(s)?
Fe(s) + 2 HCl(aq)  FeCl2(aq) + H2(g)
A)
B)
C)
D)
E)
1.10 L
0.548 L
3.55 L
0.274 L
none of the above
19. A 10.0-g sample of sodium chloride was placed in 10.0 g of water. If 3.85 g of Cl2 was obtained,
what was the percent yield of Cl2 ?
2NaCl(aq) + H2O → Cl2(g) + H2(g) + 2NaOH(aq)
A)
B)
C)
D)
E)
9.77%
31.7%
19.3%
63.5%
none of the above
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9AM
CHEM 1A – B.Kunkel
Practice Final Exam
F2014
20. A 9.70-g piece of solid CO2 (dry ice) is allowed to sublime in a balloon. The final volume of the
balloon is 1.00 L at 298 K. What is the pressure of the gas? R = 0.08206 L∙atm/mol∙K
A) 5.39 atm
B) 2.37  102 atm
C) 2.52 atm
D) 0.186 atm
E) none of these
21. Potassium chlorate decomposes upon heating as follows:
2KClO3(s)  2KCl(s) + 3O2(g)
A 1.12-g sample of KClO3 decomposes, and the oxygen at 23.8°C and 0.925 atm is collected. What
volume of oxygen gas will be collected, assuming 100% yield? R = 0.08206 L∙atm/mol∙K
A) 0.241 L
B) 0.92 L
C) 0.361 L
D) 0.0289 L
E) none of the above
22. In a quantitative analysis study, 1.878 grams of a compound containing carbon, hydrogen and
oxygen yielded 3.258 g of CO2 and 1.778 g of H2O in a combustion analysis apparatus. Determine the
empirical formula of the compound.
A)
B)
C)
D)
E)
C3H8O2
C2H3O2
C3H5O2
C3H7O2
none of the above
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9AM
CHEM 1A – B.Kunkel
Practice Final Exam
F2014
23. An unknown acid, H2X, requires 26.66 mL of a 0.117 M NaOH solution to completely neutralize
0.845 g of the acid sample. What is the molar mass of the acid?
A)
B)
C)
D)
E)
641 g/mol
542 g/mol
271 g/mol
135 g/mol
none of the above
24. After balancing the following reaction in basic conditions, what is the sum of ALL the coefficients
in the equation?
CrO42(aq) + Br(aq)  CrO2(aq) + BrO3 (aq)
A)
B)
C)
D)
E)
6
9
14
10
none of the above
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9AM
CHEM 1A – B.Kunkel
Practice Final Exam
F2014
25. Suppose 30.9 g of potassium chloride is dissolved in 350. mL of a 0.400 M aqueous solution of
silver nitrate. Calculate the final molarity of the chloride anion in solution. Assume that the volume of
the solution doesn’t change when the potassium chloride is dissolved in it.
A) 0 M
B) 1.18 M
C) 0.400 M
D) 0.783 M
E) none of the above
26. Balance the following reaction in acidic conditions. If a 74.8 mL sample of a solution of
H2C2O4 (aq) requires 27.5 mL of a 0.037 M KMnO4 solution for a complete reaction, what is the
concentration of H2C2O4 in the original solution?
MnO4(aq) + H2C2O4(aq) +  Mn2+(aq) + CO2(g)
A)
B)
C)
D)
E)
7.7  10–2 M
1.4  10–2 M
5.4  10–3 M
3.4  10–2 M
none of the above
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9AM
CHEM 1A – B.Kunkel
Practice Final Exam
F2014
27. At 1000 K, the equilibrium constant for the following reaction
2NO (g) + Br2 (g)
2NOBr (g)
is Kp = 0.013. Calculate Kp for the reverse reaction,
2NOBr (g)
2NO (g) + Br2 (g).
A) 0.99
B) 77
C) 0.013
D) 1.6 x 10-4
E) none of the above
28. A gaseous compound has the empirical formula NO2. A 5.25 gram sample of the gas occupies a
volume of 1.00 liter and exerts a pressure of 1.26 atmospheres at - 4.0 C. What is its molecular formula?
A) NO
B) NO2
C) N3O6
D) N2O4
E) none of the above
29. When 0.40 mole of SO2 and 0.60 mol of O2 are placed in an evacuated 1.00 liter flask, the reaction
below occurs. After the reactants and the product reach equilibrium and the initial temperature is
restored, the flask is found to contain 0.3 mol of SO3. Based on these results, what is the equilibrium
constant, K for this reaction?
2 SO2 (g) + O2 (g)
2 SO3 (g)
A)
B)
C)
D)
E)
20
5.0
6.7
2.0
none of the above
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9AM
CHEM 1A – B.Kunkel
Practice Final Exam
F2014
30. A 5.42-liter sample of gas was collected over water when the temperature was 24°C and the
barometric pressure was 706 torr. The dry sample of gas had a mass of 5.60 g. What is the mass of three
moles of the dry gas? The vapor pressure of water at 24°C is 22 torr.
A) 84 g
B) 14 g
C) 28 g
D) 7.0 g
E) none of the above
31. Which of the following statement about gases is(are) true?
i. Real gases act more like ideal gases as the temperature increases
ii. At 1 atm and 273 K, every molecule in a sample of gas has the same speed
iii. At constant T, CO2 molecules at 1 atm and H2 molecules at 5 atm have the same average kinetic
energy (assume CO2 and H2 are ideal gases)
A)
B)
C)
D)
E)
i only
ii only
iii only
i and iii
ii and iii
32. Consider the following equilibrium reaction. If 2.00 mole of NOCl and 1.888 mole of Cl2 (g) are
placed in a 2.00-L container, what is the equilibrium concentration of NO (g)?
2 NOCl (g)
2 NO (g) + Cl2 (g)
K = 1.6 x 105
A)
B)
C)
D)
E)
2.06 x 103 M
4.12 x 103 M
5.82 x 103 M
9.44 x 101 M
none of the above
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9AM
CHEM 1A – B.Kunkel
Practice Final Exam
F2014
33. What is the total pressure of a mixture created by adding 0.15 moles He(g) to a 5.0-L flask that
contains 570 torr of N2 (g) and 0.20 atm Ar(g) at 100°C?
A) 1.10 atm.
B) 1.33 atm.
C) 1.61 atm.
D) 1.87 atm.
E) none of the above
34. Consider a solution of HF (aq) at equilibrium at 25 °C. If NaF (aq) is added at 25 °C, what will
happen to the pKa?
A) increase
B) decrease
C) no change
35. For a substance that remains a gas under all the conditions listed, deviations from the expected
values found using the ideal gas law would be the greatest at
A)
B)
C)
D)
E)
100°C and 1.0 atm.
0°C and 1.0 atm.
100°C and 1.0 atm.
100°C and 3.0 atm.
100°C and 3.0 atm.
36. A sample of nitrogen gas was collected by displacement of water in a gas collection flask. The total
pressure in the collection flask was measured as 754.2 torr, the temperature was 20.0 °C, and the
measured volume of gas collected was 516 mL. At 20.0 °C, the vapor pressure of water is 17.5 torr.
How many grams should the nitrogen gas weigh?
A)
B)
C)
D)
E)
0.291 g
0.305 g
0.582 g
0.610 g
none of the above
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9AM
CHEM 1A – B.Kunkel
Practice Final Exam
F2014
37. What volume (L) of gas is produced from the decomposition of 35.9 g of NH 4NO2 (s) at 525 °C and
1.5 atm?
NH4NO2 (s) → N2 (g) + 2 H2O (g)
A)
B)
C)
D)
E)
24
48
15
73
none of the above
38. The following reaction has Kc = 24.4 at 300 K. Initially 2.00 moles of HX were put into a 3.00 liter
container. The reaction was allowed to come to equilibrium at 300 K. How many moles of H2(g) will
be present when the reaction reaches equilibrium?
H2(g) + X2(g)
2HX(g),
A)
B)
C)
D)
E)
0.288 moles
0.0951 moles
0.134 moles
0.404 moles
none of the above
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9AM
CHEM 1A – B.Kunkel
Practice Final Exam
F2014
39. The pH of 0.80 M benzenesulfonic acid is 0.51. What is the percent ionization of benzenesulfonic
acid?
A) 25%
B) 39%
C) 51%
D) 64%
E) none of the above
40. What is the pH of an aqueous solution that is 1.0 M HClO (Ka = 3.0 x 108) and 0.75 M NaClO?
A) 7.64
B) 7.40
C) 6.36
D) 7.52
E) none of the above
41. For nitrous acid, HNO2, Ka = 4.0  10–4. Calculate the pH of 0.28 M HNO2.
A) 12.0
B) 1.98
C) 3.40
D) 0.55
E) none of the above
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9AM
CHEM 1A – B.Kunkel
Practice Final Exam
F2014
42. At 450.0 K the equilibrium constant, Kc, for the following reaction is 4.62. The initial
concentrations are as follows: [SO3] = 0.0254, M [O2] = 0.00855 M , [SO2] = 0.500 M. Which
direction will the reaction proceed?
2SO2(g) + O2(g)
2SO3(g)
A)
B)
C)
D)
E)
Q > K, shift to the right
Q > K, shift to the left
Q < K, shift to the right
Q < K, shift to the left
no shift
43. What is the pH of a 0.35 M aqueous solutions of CH3NH2 (a base, Kb = 4.4 x 104)?
A) 13.5
B) 3.81
C) 12.09
D) 1.91
E) none of the above
44. What is the pH of a 1.00 molar solution of NaCN(aq)? The Ka for HCN = 6.2 × 1010.
A)
B)
C)
D)
E)
2.40
9.21
7.0
11.60
none of the above
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9AM
CHEM 1A – B.Kunkel
Practice Final Exam
F2014
45. Using this data,
2 NO(g) + Cl2(g)
2 NOCl(g)
2 NO2(g)
2 NO(g) + O2(g)
calculate a value for Kc for the reaction,
NOCl(g) + ½ O2(g)
A)
B)
C)
D)
E)
Kc = 3.20 x 103
Kc = 15.5
NO2(g) + ½ Cl2(g)
17.9
4.24 x 103
0.223
4.49
none of the above
46. Given the following exothermic reaction, which one of the following actions will cause an increase
in the equilibrium concentration of NO(g) in a closed reaction chamber?
2NO(g) + O2(g)
2NO2(g)
A)
B)
C)
D)
E)
increasing the pressure of the system while temperature is kept constant
increasing the temperature of the system
removing the NO2(g) from the system
more than one of the above (A-C)
none of the above
47. The pH of a 0.134 M solution of a weak base is 10.93 at 25°C. Calculate the pH of a 0.0324 M
solution of the base at 25°C.
A) 10.62
B) 11.54
C) 2.64
D) 10.93
E) none of the above
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9AM
CHEM 1A – B.Kunkel
Practice Final Exam
F2014
48. You have 500.0 mL of a buffer solution containing 0.30 M acetic acid (HC2H3O2) and 0.20 M
sodium acetate (NaC2H3O2). What will the pH of this solution be after the addition of 20.0 mL of
1.00 M HCl solution? [Ka = 1.8 x 105]
A)
B)
C)
D)
E)
4.41
5.07
4.74
4.56
none of the above
49. If a small amount of a strong base is added to a buffer made up of a weak acid, HA, and the sodium
salt of its conjugate base, NaA, the pH of the buffer solution does not change appreciably because
A) the Ka of HA is changed
B) no reaction occurs
C) the strong base reacts with A to give HA, which is a weak acid
D) the strong base reacts with HA to give AOH and H+
E) the strong base reacts with HA to give A , which is a weak base
50. A strong acid and a weak base are mixed to produce salt and water. The salt is dried and added to
pure water. The pH of the salt solution is:
A) less than seven.
B) seven.
C) greater than seven.
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9AM
CHEM 1A – B.Kunkel
Practice Final Exam
F2014
51. Solution A is composed of aqueous hydrofluoric acid (pK.=3.14). Solution B is composed of
aqueous acetic acid (pK.=4.74). Which solution has the higher pH?
A) Solution A
B) Solution B
C) The pH of the two solutions is the same
D) Cannot be determined without more information
52. When 0.100 mole of an unknown soluble salt is dissolved in 1.00 L of water, the pH of the solution
is 8.07. Assume the volume of the solid salt is negligible. What is the identity of the salt?
A) NaCN
B) NaC2H3O2
C) NaCl
D) NaF
E) NaOCl
53. The value of Ksp for AgI is 1.5  10–16. Calculate the equilibrium concentration of Ag+ in a 0.44 M
NaI solution.
A) 1.2  10–8 mol/L
B) 3.4  10–16 mol/L
C) 2.7  10–9 mol/L
D) 6.6  10–17 mol/L
E) 1.8  10–8 mol/L
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9AM
CHEM 1A – B.Kunkel
Practice Final Exam
F2014
54. A 65.0-mL sample of 0.12 M HNO2 (Ka = 4.0  10–4) is titrated with 0.11 M NaOH. What is the pH
after 28.4 mL of NaOH has been added?
A) 10.43
B) 7.00
C) 3.57
D) 3.00
E) 3.22
End of Practice Final
ANSWERS: 1. B
2. E
13. D 14. C 15. C
26. D 27. B 28. D
39. B 40. B 41. B
52. D 53. B 54. E
3. C
16. D
29. A
42. C
4. A
17. B
30. A
43. C
5. C
18. A
31. D
44. D
6. B
19. D
32. B
45. D
7. B
20. A
33. D
46. B
8.C
21. C
34. C
47. A
9. A
22. A
35. D
48. A
10. B
23. B
36. C
49. E
11. B
24. B
37. D
50. A
12.
25.
38.
51.
E
D
A
D