Download Name AP Chemistry Take Home Quiz – Due Thursday, 1/9/2014

Name _____________________
AP Chemistry
Take Home Quiz – Due Thursday, 1/9/2014
Bubble the correct answer on your scantron for each of the following.
1. Barium sulfate is LEAST soluble in a 0.01-molar solution of which of the following?
a. Al2(SO4)3
b. (NH4)2SO4
c. Na2SO4
d. NH3
e. BaCl2
2. Which of the following compounds is NOT appreciably soluble in water but is soluble in dilute hydrochloric
acid?
a. Mg(OH)2(s)
b. (NH4)2CO3(s)
c. CuSO4(s)
d. (NH4)2SO4(s)
e. Sr(NO3)2(s)
3. How many milliliters of water must be added to 10 milliliters of an HCl solution with a pH of 1 to produce a
solution with a pH of 3?
a. 10 mL
b. 90 mL
c. 100 mL
d. 990 mL
e. 1000 mL
4. Which atom in its ground state has the most unpaired electrons?
a. Ge
b. As
c. Se
d. Br
e. Ga
5. Which of the following is the correct equilibrium expression for the hydrolysis of CO32-?
a. K = [HCO3-] / ([CO32-] [H3O+])
b. K = ([HCO3-] [OH-] ) / [CO32-]
2c. K = ([CO3 ] [OH ]) / [HCO3 ]
d. K = [CO32-] / ([CO2] [OH-]2)
+
2e. K = ([CO3 ] [H3O ]) / [HCO3-]
6. A 1-molar solution of which of the following salts has the highest pH?
a. NaNO3
b. Na2CO3
c. NH4Cl
d. NaHSO4
e. Na2SO4
7.
HSO4- + H2O qe H3O+ + SO42In the equilibrium represented above, the species that act as bases include which of the following?
I. H2O
II. HSO4III. SO42a. II only
b. III only
c. I and II
d. I and III
e. II and III
8. A sample of 0.0100 mole of oxygen gas is confined at 37° C and 0.216 atmosphere. What would be the pressure
of this sample at 15° C and the same volume?
a. 0.0876 atm
b. 0.175 atm
c. 0.201 atm
d. 0.233 atm
e. 0.533 atm
9. Cr2O72-(aq) + 3Sn2+(aq) + 14H+(aq)  2Cr3+(aq) + 3Sn4+(aq) + 7H2O
Which of the following statements about this reaction is true?
a. dichromate ions are oxidized by Sn(II) ions
b. hydrogen ions are reduced to H2O
c. oxygen is reduced from -2 to 0
d. the oxidation state of chromium does not change
e. chromium is reduced from the +6 to the +3 oxidation state
10. What is the molar solubility in water of Ag2CrO4? (The Ksp for Ag2CrO4 is 8 x 10-12.)
a. 8 x 10-12 M
b. 2 x 10-12 M
c. (4 x 10-12 M)1/2
-12
1/3
-12
1/3
d. (4 x 10 M)
e. (2 x 10 M)
11. Which of the following pairs of compounds can be used to illustrate the law of multiple proportions?
a. H2O and H2O2
b. HCl and HClO3
c. KBr and KCl
d. NH3 and NH4Cl
e. AgNO3 and Ag2SO3
12. Oxygen, which is 16 times as dense as hydrogen, diffuses:
a. 1/16 times as fast.
b. 1/4 times as fast.
c. 4 times as fast.
d. 16 times as fast
e. equally as fast as hydrogen.
13. The density of an unknown gas is 4.20 grams per liter at 3.00 atmospheres pressure and 127 °C. What is the
molecular weight of this gas? (R = 0.0821 liter-atm / mole-K)
a. 14.6
b. 46.0
c. 88.0
d. 94.1
e. 138
14. A pure sample of KClO3 is found to contain 71 grams of chlorine atoms. What is the mass of the sample?
a. 122 grams
b. 170 grams
c. 209 grams
d. 245 grams
e. 293 grams
15. MnS(s) + 2H+ <===> Mn2+ + H2S(g) At 25 °C the solubility product constant, Ksp, for MnS in 5 x 10-15 and the
acid dissociation constants K1 and K2 for H2S are 1 x 10-7 and 1 x 10-13, respectively. What is the equilibrium
constant for the reaction represented by the equation above at 25°C?
a. 1 x 10-13 / 5 x 10-15
b. 5 x 10-15 / 1 x 10-7
c. 1 x 10-7 / 5 x 10-20
-15
-20
-20
e. 1 x 10 / 5 x 10-15
d. 5 x 10 / 1 x 10
16. 2MnO4- + 5SO32- + 6H+  2Mn2+ + 5 SO42- + 3H2O
Which of the following statements is true regarding the reaction given above?
a. MnO4- acts as the reducing agent
b. H+ acts as the oxidizing agent
2c. SO3 acts as the reducing agent d. MnO4 is oxidized
e. SO32- is reduced
17. Equal volumes of 0.10-molar H3PO4 and 0.20-molar KOH are mixed. After equilibrium is established, the type
of ion in solution in largest concentration, other than the K+ ion, is
a. H2PO4¯
b. HPO42c. PO43d. OHe. H3O+
18. A student examined 2.0 moles of an unknown carbon compound and found that the compound contained 48
grams of carbon, 64 grams of oxygen and 8 grams of hydrogen. Which of the following could be the molecular of
the compound?
a. CH2O
b. CH2OH
c. CH3COOH d. CH3CO
e. C2H5OH
19. Which of the following will produce a buffered solution?
I. Equal volumes of 1 M NH3 and 1 M HC2H3O2 solutions are mixed.
II. Equal volumes of 1 M H2CO3 and 1 M KHCO3 solutions are mixed.
III. Equal volumes of 0.1 M NH3 and 0.1 M NH4Cl solutions are mixed.
a. I only
b. III only
c. I and II only
d. II and III only e. I, II and III
20. If the acid dissociation constant, Ka, for an acid HA is 8 x 10-4 at 25 °C, what percent of the acid is dissociated
in a 0.50-molar solution of HA at 25 °C?
a. 0.08%
b. 0.2%
c. 1%
d. 2%
e. 4%
21. How much water must be added to a 50.0 mL solution of 0.60 M HNO3 to produce a 0.40 M solution of HNO3?
a. 25 mL
b. 33 mL
c. 50 mL
d. 67 mL
e. 75 mL
22. Each of the following compounds was added to distilled water at 25°c. Which one produced a solution with a
pH that was greater than 7?
a. N2
b. O2
c. NaI
d. MgO
e. SO2
23. Which of the following elements forms a polyatomic anion where it has an oxidation number of +6?
a. Ca
b. S
c. Fe
d. N
e. Cs
24. A sealed isothermal container initially contained 2 moles of CO gas and 3 moles of H2 gas. The following
reversible reaction occurred:
CO(g) + 2H2(g) qe CH3OH(g)
At equilibrium, there was 1 mole of CH3OH in the container. What was the total number of moles of gas present in
the container at equilibrium?
a. 1
b. 2
c. 3
d. 4
e. 5
25. What is the volume of 0.05 molar HNO3 that is required to neutralize 100 mL of a 0.10 molar Ca(OH)2
solution?
a. 100 mL
b. 200 mL
c. 300 mL
d. 400 mL
e. 500 mL
26. CH3CH2OH boils at 78 °C and CH3OCH3 boils at - 24 °C, although both compounds have the same composition.
This difference in boiling points may be attributed to a difference in
a. molecular mass
b. density
c. specific heat
d. hydrogen bonding
e. heat of combustion
27. HCl(aq) + AgNO3(aq)  AgCl(s) + HNO3(aq)
One half liter of a 0.20 molar HCl solution is mixed with one-half liter of a 0.40 molar solution of AgNO3. A
reaction occurs forming a precipitate as shown above. If the reaction goes to completion, what is the mass of AgCl
produced?
a. 14 grams
b. 28 grams
c. 42 grams
d. 70 grams
e. 84 grams
28. When the following half reaction is balanced with the smallest whole number coefficients, it will contain:
NO3-  NO
a. 2e- on the right side
b. 4e- on the left side
c. 2H2O on the right side
+
d. 2H on the left side
e. a coefficient of 2 for NO
29. The solubility of CuI is 2 x 10-6 molar. What is the solubility product constant, Ksp, for CuI?
a. 1.4 x 10-3
b. 2 x 10-6
c. 4 x 10-12
d. 2 x 10-12
e. 8 x 10-18
30. 2 ZnS(s) + 3 O2(g)  2 ZnO(s) + 2 SO2(g)
If the reaction above took place at standard temperature and pressure, what was the volume of O2(g) required to
produce 40.0 grams of ZnO(s)?
(40.0)(2)
(40.0)(3)
(40.0)(2)(22.4)
a.
L
b.
L
c.
L
(81.4)(3)(22.4)
(81.4)(2)(22.4)
81.4)(3)
d.
(40.0)(3)(22.4)
L
(81.4)(2)
e.
(81.4)(2)(22.4)
L
(40.0)(3)
31. What is the percent composition by mass of the elements in the compound NaNO3?
a. Na 20%, N 20%, O 60%
b. Na 23%, N 14%, O 48%
c. Na 23%, N 14%, O 63%
d. Na 27%, N 16%, O 57%
e. Na 36%, N 28%, O 36%
32. CH4(g) + 2 O2(g)  CO2(g) + 2 H2O(l); ΔH = - 889.1 kJ
ΔHf° H2O(l) = - 285.8 kJ / mole
ΔHf° CO2(g) = - 393.3 kJ / mole
What is the standard heat of formation of methane, ΔHf° CH4(g), as calculated from the data above?
a. -107.5 kJ/mole
b. -75.8 kJ/mole
c. -210.0 kJ/mole
d. 75.8 kJ/mole
e. 210.0 kJ/mole
33. At constant temperature and pressure, the heats of formation for H2O(g), CO2(g) and C2H6(g) are as follows:
Species
∆H (kJ/mole)
H2O(g)
-251
CO2(g)
-393
C2H6(g)
-84
If ∆H values are negative for exothermic reactions, what is the ∆H for 1 mole of C2H6 gas to oxidize to carbon
dioxide gas and water vapor (temperature and pressure are held constant)?
a. -8730 kJ/mole
b. -2910 kJ/mole
c. -1455 kJ/mole
d. 1455 kJ/mole
e. 2910 kJ/mole
34. pH is equal to pKa:
a. at the equivalence point of a titration
b. when [acid] = [conjugate base]
c. in the buffer region
d. in the Henderson-Hasselbach equation
e. at equilibrium
35. Which of the following is the acid anhydride of a monoprotic acid?
a. N2O5
b. SO3
c. FeO
d. CO2
e. CaO
36. The acid dissociation constant for HClO is 3.0 x 10-8. What is the hydrogen ion concentration in 0.12 M
solution of HClO?
a. 3.6 x 10-9 M b. 3.6 x 10-8 M c. 6.0 x 10-8 M d. 2.0 x 10-5 M e. 6.0 x 10-5 M
Compound
FeS
PbS
MnS
Ksp at 25°C
6.33 x 10-18
8.03 x 10-28
1.03 x 10-13
37.
The molecular formula for the hydrated ferric oxide is generally
written as Fe2O3 * x H2O because the water content in rust can vary. If a 1-molar sample of hydrated ferric oxide is
found to contain 108 g of H2O, what is the molecular formula of the compound?
a. Fe2O3 * H2O
b. Fe2O3 * 3H2O
c. Fe2O3 * 6H2O
d. Fe2O3 * 10H2O
e. Fe2O3 * 12H2O
38. The density of a gas is directly proportional to its
a. pressure
b. volume
c. kinetic energy
d. temperature
e. molecular velocity
39. Which of the following elements most readily shows the photoelectric effect?
a. noble gases
b. alkali metals
c. halogen elements
d. transition metals
e. the chalcogens
40. A piece of metal weighing 418.6 grams was put into a boiling water bath. After 10 minutes, the metal was
immediately placed in 250.0 grams of water at 40.0°C. The maximum temperature that the system reached was
50.0 °C. What is the specific heat of the metal? The specific heat of the water is 4.186 J/g°C.
a. 0.500 J/g°C b. 1.00 J/g°C
c. 2.00 J/g°C
d. 4.00 J/g°C
e. 8.00 J/g°C
41. In expanding from 5.00 to 6.00 liters at a constant pressure of 2.00 atmospheres, a gas absorbs 505.64 joules of
energy (101.32 J = 1 liter atm). The change in energy ∆E for the gas is:
a. 50.66 J
b. 101.32 J
c. 303.00 J
d. 505.64 J
e. 606.00 J
42. A solution at 25°C contains Fe2+, Pb2+, and Mn2+ ions. Which of the following gives the order in which
precipitates will form, from first to last, as Na2S is steadily added to the solution?
a. FeS, PbS, MnS
b. MnS, PbS, FeS
c. FeS, MnS, PbS
d. PbS, FeS, MnS
e. MnS, FeS, PbS
43.
HC2H3O2(aq) + CN-(aq) qe HCN(aq) + C2H3O2-(aq)
The reaction represented above has an equilibrium constant equal to 3.7 x 104. Which of the following can be
concluded from this information?
a. CN-(aq) is a stronger base than C2H3O2-(aq)
b. HCN(aq) is a stronger acid than HC2H3O2(aq)
c. The conjugate base of CN-(aq) is C2H3O2-(aq)
d. The equilibrium constant will increase with an increase in temperature.
e. The pH of a solution containing equimolar amounts of CN-(aq) and HC2H3O2(aq) is 7.0.
44. Given a molecule with the general formula AB2, which one of the following would be the most useful in
determining whether the molecule was bent or linear?
a. ionization energies
b. electron affinities
c. dipole moments
d. electronegativities
e. bond energies
45. For a certain reaction at 298K, the value of K is 1.2 x 10-3. At 323K the value of K is 3.4 x 10-1. This means
that the reaction is:
a. endothermic.
b. exothermic.
c. never favorable.
d. More information is needed.
e. None of these.
46. 6.0 moles of chlorine gas are placed in a 3.0 L flask at 1250 K. At this temperature, the chlorine molecules
begin to dissociate into chlorine atoms. What is the value of Kc, if 50.% of the chlorine molecules dissociate when
equilibrium has been achieved?
a. 1.0
b. 3.0
c. 4.0
d. 6.0
e. 12.0
47. A gaseous mixture containing 7.0 moles of nitrogen, 2.5 moles of oxygen, and 0.50 mole of helium exerts a
total pressure of 0.90 atmosphere. What is the partial pressure of the nitrogen?
a. 0.13 atm
b. 0.27 atm
c. 0.63 atm
d. 0.90 atm
e. 6.3 atm
48. Sulfur trioxide gas dissociates into sulfur dioxide gas and oxygen gas at 1250°C. In an experiment 3.60 moles
of sulfur trioxide were placed into an evacuated 3.0 L flask. The concentration of sulfur dioxide gas measured at
equilibrium was found to be 0.20 M. What is the equilibrium constant Kc, for the reaction?
a. 1.6 x10-4
b. 1.0 x 10-3
c. 2.0 x 10-3
d. 4.0 x 10-3
e. 8.0 x 10-3
49. It takes 40.0 mL of 0.100 M NaOH to titrate 488 mg of a solid monoprotic acid to the phenolphthalein endpoint.
What is the molecular mass of the acid?
a. 221
b. 122
c. 68
d. 1.2 x 105
e. 1.2 x 10-1
50. When excess hydroxide ions were added to 1.0 liter of CaCl2 solution, Ca(OH)2 precipitate was formed. If all
the calcium ions in the solution were precipitated in 7.4 grams of Ca(OH)2, what was the initial concentration of the
CaCl2 solution?
a. 0.05 molar
b. 0.10 molar
c. 0.15 molar
d. 0.20 molar
e. 0.30 molar
51. How many grams of carbon are present in 270. grams of glucose, C6H12O6?
a. 12.0 grams
b. 18.0 grams
c. 67.5 grams
d. 72.0 grams
e. 108 grams
52. What is the weight of NaNO3 (molecular weight 85.0) present in 100. mL of a 4.00 molar solution?
a. 8.50 grams
b. 17.0 grams
c. 25.5 grams d. 34.0 grams
e. 51.0 grams
53. A method of separation where a mobile phase is passed through a stationary phase is called:
a. distillation
b. decanting
c. filtration
d. electrolysis e. chromatography
54. The equilibrium constant for the reaction: CO(g) + H2O(g) qe CO2(g) + H2(g) is 26 at 50ºC. What is the Kc
for 3CO2(g) + 3H2(g) qe 3CO(g) + 3H2O(g) at the same temperature?
c. 0.038
d. 5.7 x 10-5
e. 2.9
a. 0.34
b. 1.8 x 104
55. 100 grams of O2(g) and 100 grams of He(g) are in separate containers of equal volume. Both gases are at
100ºC. Which of the following statements is true?
a. Both gases would have the same pressure.
b. The average kinetic energy of the O2 molecules is greater than that of the He molecules.
c. The pressure of the He(g) would be greater than that of the O2(g).
d. There are equal numbers of He molecules and O2 molecules.
e. The average kinetic energy of the He molecules is greater than that of the O2 molecules.
56. A 3.00-liter flask initially contains 1.50 mol of gas A and 0.450 mol of gas B. Gas A decomposes according to
the following reaction: 3A qe 2B + C The equilibrium concentration of gas C is 0.100 mol/L. Determine the
equilibrium concentration of gas A.
a. 0.500 M
b. 0.100 M
c. 0.300 M
d. 0.200 M
e. none of these
57. The Ka for hydrofluoric acid is 6.8 x 10-4. What percentage of HF is dissociated in a 0.080 M solution where
the hydronium ion concentration is 7.4 x 10-3 M?
a. 1.12%
b. 4.25%
c. 9.2 %
d. 12.3%
e. 23.6%
58. A molecule or an ion is classified as a Lewis acid if it
a. accepts a proton from water
b. accepts a pair of electrons to form a bond
c. donates a pair of electrons to form a bond
d. donates a proton to water
e. has resonance Lewis electron-dot structures
59. How many moles of NaF must be dissolved in 1.00 liter of a saturated solution of PbF2 at 25°C to reduce the
[Pb2+] to 1 x 10-6 molar? (Ksp of PbF2 at 25°C = 4.0 x 10-8)
a. 0.020 mole
b. 0.040 mole
c. 0.10 mole
d. 0.20 mole
e. 0.40 mole
60. Which of the following cannot be a reducing agent?
a. Ag
b. Ic. Fe3+
d. Cr3+
e. Cl-
61. How many grams of NaOH (molar mass = 40.0 g/mol) are contained in 5.00 x 102 mL of a 0.80 M sodium
hydroxide solution?
a. 16 g
b. 80. g
c. 20. g
d. 64 g.
e. none of these
62. Which of the following statements is correct?
a. HClO2 is a stronger acid than HClO3
b. HI is a weaker acid than HCl
d. HNO3 is a stronger acid than HNO2
c. H3PO4 is a stronger acid than HClO4
e. CH3COOH is a stronger acid than CH2BrCOOH
63. Which of the following statements correctly describes the signs of q and w for the following exothermic process
at P = 1 atm and T = 370 K? H2O(g)  H2O(l)
a. q is negative, w is positive
b. q and w are negative
c. q and w are both positive
d. q is positive, w is negative
e. q and w are both zero.
64. The compound that contains 10.4% oxygen is:
a. NaOH
b. CaO
c. Al2O3
d. BaO
65. A halogen, X, and an alkaline earth metal, M, can form a compound with the formula:
a. MX
b. MX2
c. MX3
d. M2X3
e. Ca(OH)2
e. M3X2
66. The Ka of hydrocyanic acid, HCN, is 5.0×10–10. What is the pH of 0.050 M HCN(aq)?
a. below 3.5
b. between 3.5 and 4.5
c. between 5.0 and 5.5
d. between 9.0 and 9.5
e. between 10.5 and 11.0