Combo with AP Chem 1984 MC and 4 others
24. The formula for potassium hexacyanoferrate(II) is (A) K4[Fe(CN)6] (B) K3[Fe(CN)6] (C) K2[Pt(CN)4] (D) K2[Pt(CN)6] (E) KCN
A
19. In which of the following compounds is the mass ratio of chromium to oxygen closest to 1.62 to 1.00 ? (A) CrO3 (B) CrO2 (C) CrO (D) Cr2O (E) Cr2O3
B
23. 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
B
58. N2(g) + 3 H2(g) ---> 2 NH3(g) The reaction indicated above is thermodynamically spontaneous at 298 K, but becomes nonspontaneous at higher temperatures. Which of the following is true at 298 K? (A) DG, DH, and DS are all positive. (B) DG, DH, and DS are all negative. (C) DG and DH are negative, but DS is positive. (D) DG and DS are negative, but DH is positive. (E) DG and DH are positive, but DS is negative.
B
71. In a qualitative ananlysis for the presence of Pb2+, Fe2+, and Cu2+ ions in a aqueous solution, which of the following will allow the separation of Pb2+ from the other ions at room temperature? A) Adding dilute Na2S(aq) solution B) Adding dilute HCl(aq) solution C) Adding dilute NaOH(aq) solution D) Adding dilute NH3(aq) solution E) Adding dilute HNO3(aq) solution
B
71. In the electroplating of nickel, 0.200 faraday of electrical charge is passed through a solution of NiSO4. What mass of nickel is deposited? (A) 2.94 g (B) 5.87 g (C) 11.7 g (D) 58.7 g (E) 294 g
B
74. A pure, white crystalline solid dissolves in water to yield a basic solution that liberates a gas when excess acid is added to it. On the basis of this information, the solid could be (A) KNO3 (B) K2CO3 (C) KOH (D) KHSO4 (E) KCl
B
74. Equal volumes of 0.10-molar H3PO4 and 0.20-molar KOH are mixed. After equilibrium is established, the type of ion an solution in largest concentration, other than the K+ ion, is (A) H2PO4¯ (B) HPO42¯ (C) PO43¯ (D) OH¯ (E) H3O+
B
Look at graph 39. On the basis of the solubility curves shown above, the greatest percentage of which compound can be recovered by cooling a saturated solution of that compound from 90˚C to 30˚C? (A) NaCl (B) KNO3 (C) K2CrO4 (D) K2SO4 (E) Ce2(SO4)3
B
Look at the Phase Diagram for 5-7 (A) Sublimation (B) Condensation (C) Solvation (D) Fusion (E) Freezing 7. If the pressure increases from 0.5 to 1.5 atmospheres at a constant temperature of 50° C, which of the processes occurs?
B
(A) 1s2 2s22p5 3s23p5 (B) 1s2 2s22p6 3s23p6 (C) 1s2 2s22p62d10 3s23p6 (D) 1s2 2s22p6 3s23p63d5 (E) 1s2 2s22p6 3s23p63d3 4s2 4. An impossible electronic configuration
C
26. How many milliliters of 11.6-molar HCl must be diluted to obtain 1.0 liter of 3.0-molar HCl? (A) 3.9 mL (B) 35 mL (C) 260 mL (D) 1,000 mL (E) 3,900 mL
C
(A) O (B) La (C) Rb (D) Mg (E) N 3. Which of the elements above has the smallest ionic radius for its most commonly found ion?
D
(A) hydrogen bonding (B) hybridization (C) ionic bonding (D) resonance (E) van der Waals forces (London dispersion forces) 14. Is used to explain the fact that the carbon-to-carbon bonds in benzene, C6H6, are identical
D
*SEE DIAGRAM ON TEST The spontaneous reaction that occurs when the cell above operates is: 2Ag+ + Cd(s) ---> 2 Ag(s) + Cd2+ (A) Voltage increases. (B) Voltage decreases but remains at zero. (C) Voltage becomes zero and remains at zero. (D) No change in voltage occures. (E) Direction of voltage change cannot be predicted without additional information. Which of the above occurs for each of the following circumstances? 15. The silver electrode is made larger.
D
15. Carbon dioxide, CO2(s) (A) Lattice of positive and negative ions held together by electrostatic forces. (B) Closely packed lattice with delocalized electrons throughout (C) Strong single covalent bonds with weak intermolecular forces. (D) Strong multiple covalent bonds (including bonds.) with weak intermolecular forces (E) Macromolecules held tgether with strong polar bonds.
D
37. A sample of 3.30 grams of an ideal gas at 150.0 °C and 1.25 atmospheres pressure has a volume of 2.00 liters. What is the molar mass of the gas? The gas constant, R, is 0.0821 L atm mol¯1 K¯1). (A) 0.0218 gram/mole (B) 16.2 grams/mole (C) 37.0 grams/mole (D) 45.8 grams/mole (E) 71.6 grams/mole
D
75. Which of the following pairs of liquids forms the solution that is most ideal (most closely follows Raoult's law)? A) C8H18(l) and H2O(l) B) CH3CH2CH2OH(l) and H2O(l) C) CH3CH2CH2OH(l) and C8H18(l) D) C6H14(l) and C8H18(l) E) H2SO4(l) and H2O(l)
D
81. What is the net ionic equation for the reaction that occurs when aqueous copper(II) sulfate is added to excess 6-molar ammonia? (A) Cu2+ + SO42¯ + 2 NH4+ + 2 OH¯ ---> (NH4)2SO4 + Cu(OH)2 (B) Cu2+ + 4 NH3 + 4 H2O --> Cu(OH)42¯ + 4 NH4+ (C) Cu2+ + 2 NH3 + 2 H2O --> Cu(OH)2 + 2 NH4+ (D) Cu2+ + 4 NH3 --> Cu(NH3)42+ (E) Cu2+ + 2 NH3 + H2O --> CuO + 2 NH4+
D
Look at Equation 23. Neutron bombardment of uranium can induce the reaction represented above. Nuclide X is which of the following? (A) 92 35 Br (B) 94 35 Br (C) 91 37 Rb (D) 92 37 Rb (E) 94 37 Rb
D
Questions 6-7 refer to the following solid compounds. (A) PbSO4 (B) CuO (C) KMnO4 (D) KCl (E) FeCl3 7. Is white and very soluble in water
D
52. The test for the presence of Ag+ in an unknown solution involves the treatment of the solver-ammonia complex with dilute hydrochloric acid. The appearance of a white precipitate at this point indicates the presence of silver ion in the original sample. The net ionic equation that represents this test is (A) Ag(NH4)4+ + 4 H+ <===> Ag(s) + 4 NH4+ (B) Ag(NH4)4+ + Cl¯ <===> AgCl(s) + 4 NH4+ (C) Ag(NH3)4+ + 4 HCl <===> AgCl(s) + 4 NH4+ + 3 Cl#175; (D) Ag(NH3)4+ + Cl¯ <===> Ag(NH3)2Cl(s) (E) Ag(NH3)4+ + 2 H+ + Cl#175; <===> AgCl(s) + 2 NH4+
E
(A) Activation energy (B) Free energy (C) Ionization energy (D) Kinetic energy (E) Lattice energy 2. The energy change that occurs in the conversion of an ionic solid to widely separated gaseous ions
E (Lattice Energy)
(A) NH3 and NH4Cl (B) H3PO4 and NaH2PO4 (C) HCl and NaCl (D) NaOH and NH3 (E) NH3 and HC2H3O2 (acetic acid) 11. A buffer at a pH > 8
A
18. Reacts with water to form a strong base (A) Lithium (B) Nickel (C) Bromine (D) Uranium (E) Fluorine
A
2 H2O(l) + 4 MnO4-(aq) + 3 (ClO2)-(aq) => 4MnO2(s) + 3 (ClO4)-(aq) + 4 OH-(aq) 60. According to the balanced equation above, how many moles of (ClO)2-(aq) are needed to react completely with 20. mL of 0.20 M KMnO4 solution? (A) 0.0030 mol (B) 0.0053 mol (C) 0.0075 mol (D) 0.013 mol (E) 0.030 mol
A
2 N2H4(g) + N2O4(g) => 3 N2(g) + 4 H2O(g) 58. When 8.0 g of N2H4 (32 g mol-1) and 92 g of N2O4 (92 g mol-1) are mixed together and react according to the equation above, what is the maximum mass of H2O that can be produced? (A) 9.0 g (B) 18 g (C) 36 g (D) 72 g (E) 144 g
A
27. Appropriate uses of a visible-light spectrophtometer include which of the following? I. Determining the concentration of a solution of Cu(NO3)2 II. Measuring the conductivity of a solution of KMnO4 III. Determining which ions are present in a solution that may contain Na+, Mg2+, Al3+ (A) I only (B) II only (C) III only (D) I and II only (E) I and III only
A
29. Cu(s) + 2 Ag+ ---> Cu2+ + 2 Ag(s) If the equilibrium constant for the reaction above is 3.7 x 1015, which of the following correctly describes the standard voltage, E°, and the standard free energy change, DG°, for this reaction? (A) E° is positive and DG° is negative. (B) E° is negative and DG° is positive. (C) E° and DG° are both positive. (D) E° and DG° are both negative. (E) E° and DG° are both zero
A
29. When an aqueous solution of NaOH is added to an aqueous solution of potassium dichromate, K2Cr2O7 the dichromate ion is converted to (A) CrO42¯ (B) CrO2 (C) Cr3+ (D) Cr2O3(s) (E) Cr(OH)3(s)
A
31. The structural isomers C2H5OH and CH3OCH3 would be expected to have the same values for which of the following? (Assume ideal behavior.) (A) Gaseous densities at the same temperature and pressure (B) Vapor pressures at the same temperature (C) Boiling points (D) Melting points (E) Heats of vaporization
A
32. The net ionic equation for the reaction between silver carbonate and hydrochloric acid is (A) Ag2CO3(s) + 2 H+ + 2 Cl¯ ---> 2 AgCl(s) + H2O + CO(g) (B) 2 Ag+ + CO32¯ + 2 H+ + 2 Cl¯ ---> 2 AgCl(s) + H2O + CO2(g) (C) CO32¯ + 2 H+ ---> H2O + CO2(g) (D) Ag+ + Cl¯ ---> AgCl(s) (E) Ag2CO3(s) + 2 H+ ---> 2Ag+ + H2CO3
A
33. Which of the following conclusions can be drawn from J. J. Thomson's cathode ray experiments? (A) Atoms contain electrons. (B) Practically all the mass of an atom is contained in its nucleus. (C) Atoms contain protons, neutrons, and electrons. (D) Atoms have a positively charged nucleus surrounded by an electron cloud. (E) No two electrons in one atom can have the same four quantum numbers.
A
45. The alkenes are compounds of carbon and hydrogen with the general formula CnH2n. If 0.561 gram of any alkene is burned in excess oxygen, what number of moles of H2O is formed? (A) 0.0400 mole (B) 0.0600 mole (C) 0.0800 mole (D) 0.400 mole (E) 0.800 mole
A
52. 3 Ag(s) + 4 HNO3 <===> 3 AgNO3 + NO(g) + 2 H2O The reaction of silver metal and dilute nitric acid proceeds according to the equation above. If 0.10 mole of powdered silver is added to 10. milliliters of 6.0-molar nitric acid, the number of moles of NO gas that can be formed is (A) 0.015 mole (B) 0.020 mole (C) 0.030 mole (D) 0.045 mole (E) 0.090 mole
A
56. A yellow precipitate forms when 0.5 M NaI(aq) is added to a 0.5 M solution of which of the following ions? A) Pb2+(aq) B) Zn2+(aq) C) CrO42¯(aq) D) SO42¯(aq) E) OH¯(aq)
A
57. Molecules that have planar configurations include which of the following? I. BCl3 II. CHCl3 III. NCl3 (A) I only (B) III only (C) I and II only (D) II and III only (E) I, II, and III
A
64. Equal numbers of moles of He(g), Ar(g), and Ne(g) are placed in a glass vessel at room temperature. If the vessel has a pinhole-sized leak, which of the following will be true regarding the relative values of the partial pressures of the gases remaining in the vessel after some of the gas mixture has effused? A) PHe < PNe < PAr B) PHe < PAr < PNe C) PNe < PAr < PHe D) PAr < PHe < PNe E) PHe = PAr = PNe
A
65. 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)
A
66. When solid ammonium chloride, NH4Cl(s) is added to water at 25 °C, it dissolves and the temperature of the solution decreases. Which of the following is true for the values of H and DS for the dissolving process? DH DS A) Postive Positive B) Positive Negative C) Positive Equal to zero D) Negative Positive E) Negative Negative (the dH means change in H (the triangle sign))
A
69. If 200. mL of 0.60 M MgCl2(aq) is added to 400. mL of distilled water, what is the concentration of Mg2+(aq) in the resulting solution? (Assume volumes are additive.) (A) 0.20 M (B) 0.30 M (C) 0.40 M (D) 0.60 M (E) 1.2 M
A
72. How many moles of solid Ba(NO3)2 should be added to 300. milliliters of 0.20-molar Fe(NO3)3 to increase the concentration of the NO3¯ ion to 1.0-molar? (Assume that the volume of the solution remains constant.) (A) 0.060 mole (B) 0.12 mole (C) 0.24 mole (D) 0.30 mole (E) 0.40 mole
A
73. 2 SO2(g) + O2(g) <===> 2 SO3(g) When 0.40 mole of SO2 and 0.60 mole of O2 are placed in an evacuated 1.00-liter flask, the reaction represented above occurs. After the reactants and the product reach equilibrium and the initial temperature is restored, the flask is found to contain 0.30 mole of SO3. Based on these results, the equilibrium constant, Kc for the reaction is (A) 20. (B) 10. (C) 6.7 (D) 2.0 (E) 1.2
A
75. In a saturated solution of Zn(OH)2 at 25˚C the value of [OH-] is 2.0x10^-6 M. What is the value of thesolubility-product constant, Ksp, for Zn(OH)2 at 25˚C? (A) 4.0x10^-18 (B) 8.0x10^-18 (C) 1.6x10^-17 (D) 4.0x10^-12 (E) 2.0x10^-6
A
84. Which of the following aqueous solutions has the highest boiling point? (A) 0.10 M potassium sulfate, K2SO4 (B) 0.10 M hydrochloric acid, HCl (C) 0.10 M ammonium nitrate, NH4NO3 (D) 0.10 M magnesium sulfalte, MgSO4 (E) 0.20 M sucrose, C12H22O11
A
H3AsO4 + 3I¯ + 2 H3O+ ---> H3AsO3 + I3¯ + H2O The oxidation of iodide ions by arsenic acid in acidic aqueous solution occurs according to the stoichiometry shown above. The experimental rate law of the reaction is: Rate = k [H3AsO4] [I¯] [H3O+] 26. According to the rate law for the reaction, an increase in the concentration of hydronium ion has what effect on this reaction? (A) The rate of reaction increases. (B) The rate of reaction decreases. (C) The value of the equilibrium constant increases. (D) The value of the equilibrium constant decreases. (E) Neither the rate nor the value of the equilibrium constant is changed.
A
HC2H3O2(aq) + CN¯(aq) <===> HCN(aq) + C2H3O2¯(aq) 62. 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.
A
NH4NO3(s) --> N2O(g) + 2 H2O(g) 60. A 0.03 mol sample of NH4NO3(s) is placed in a 1 L evacuated flask, which is then sealed and heated. The NH4NO3(s) decomposes completely according to the balanced equation above. The total pressure in the flask measured at 400 K is closest to which of the following? ( The value of the gas constant, R, is 0.082 L atm mol¯1 K¯1) (A) 3 atm (B) 1 atm (C) 0.5 atm (D) 0.1 atm (E) 0.03 atm
A
Questions 34-35 refer to an electrolytic cell that involves the following half-reaction. AlF63¯ + 3 e¯ ---> Al + 6F¯ 34. Which of the following occurs in the reaction? (A) AlF 63¯ is reduced at the cathode. (B) Al is oxidized at the anode. (C) Aluminum is converted from the -3 oxidation state to the 0 oxidation state. (D) F¯ acts as a reducing agent. (E) F¯ is reduced at the cathode.
A
W(g) + X(g) --> Y(g) + Z(g) 53. Gases W and X react in a closed, rigid vessel to form gases Y and Z according to the equation above. The initial pressure of W(g) is 1.20 atm and that of X(g) is 1.60 atm. No Y(g) or Z(g) is initially present. The experiment is carried out at constant temperature. What is the partial pressure of Z(g) when the partial pressure of W(g) has decreased to 1.0 atm? A) 0.20 atm B) 0.40 atm C) 1.0 atm D) 1.2 atm E) 1.4 atm
A
(A) Activation energy (B) Free energy (C) Ionization energy (D) Kinetic energy (E) Lattice energy 4. The energy required to form the transition state in a chemical reaction
A (Activation Energy)
(A) 1s2 2s22p5 3s23p5 (B) 1s2 2s22p6 3s23p6 (C) 1s2 2s22p62d10 3s23p6 (D) 1s2 2s22p6 3s23p63d5 (E) 1s2 2s22p6 3s23p63d3 4s2 6. The ground-state configuration of a negative ion of a halogen
B
(A) 1s2 2s22p5 3s23p5 (B) 1s2 2s22p6 3s23p6 (C) 1s2 2s22p62d10 3s23p6 (D) 1s2 2s22p6 3s23p63d5 (E) 1s2 2s22p6 3s23p63d3 4s2 7. The ground-state configuration of a common ion of an alkaline earth element
B
(A) NH3 and NH4Cl (B) H3PO4 and NaH2PO4 (C) HCl and NaCl (D) NaOH and NH3 (E) NH3 and HC2H3O2 (acetic acid) 12. A buffer at a pH < 6
B
(A) hydrogen bonding (B) hybridization (C) ionic bonding (D) resonance (E) van der Waals forces (London dispersion forces) 13. Is used to explain the fact that the four bonds in methane are equivalent
B
14. Gold, Au(s) (A) Lattice of positive and negative ions held together by electrostatic forces. (B) Closely packed lattice with delocalized electrons throughout (C) Strong single covalent bonds with weak intermolecular forces. (D) Strong multiple covalent bonds (including bonds.) with weak intermolecular forces (E) Macromolecules held tgether with strong polar bonds.
B
20. What mass of Au is produced when 0.0500 mol of Au2S3 is reduced completely with excess H2? (A) 9.85 g (B) 19.7 g (C) 24.5 g (D) 39.4 g (E) 48.9 g
B
21. In the laboratory, H2(g) can be produced by adding which of the following to 1 M HCl(aq)? I. 1 M NH3(aq) II. Zn(s) III. NaHCO3(s) (A) I only (B) II only (C) III only (D) I and II only (E) I, II, and Ill
B
21. When a sample of oxygen gas in a closed container of constant volume is heated until its absolute temperature is doubled, which of the following is also doubled? (A) The density of the gas (B) The pressure of the gas (C) The average velocity of the gas molecules (D) The number of molecules per cm3 (E) The potential energy of the molecules
B
24. The mass of element Q found in 1.00 mole of each of four different compounds is 38.0 grams, 57.0 grams, 76.0 grams, and 114 grams, respectively. A possible atomic weight of Q is (A) 12.7 (B) 19.0 (C) 27.5 (D) 38.0 (E) 57.0
B
26. Approximately what mass of CuSO4•5H2O (250 g mol-1) is required to prepare 250 mL of 0.10 M copper(II) sulfate solution? (A) 4.0 g (B) 6.2 g (C) 34 g (D) 85 g (E) 140 g
B
2NO(g) + O2(g) <===> 2 NO2(g) H < 0 54. Which of the following changes alone would cause a decrease in the value of Keq for the reaction represented above? A) Decreasing the temperature B) Increasing the temperature C) Decreasing the volume of the reaction vessel D) Increasing the volume of the reaction vessel E) Adding a catalyst
B
32. Which of the following oxides is a gas at 25˚C and 1 atm? (A) Rb2O (B) N2O (C) Na2O2 (D) SiO2 (E) La2O3
B
46. If 0.060 faraday is passed through an electrolytic cell containing a solution of In3+ ions, the maximum number of moles of In that could be deposited at the cathode is (A) 0.010 mole (B) 0.020 mole (C) 0.030 mole (D) 0.060 mole (E) 0.18 mole
B
48. If 87.5 percent of a sample of pure 131I decays in 24 days, what is the half-life of 131I? (A) 6 days (B) 8 days (C) 12 days (D) 14 days (E) 21 days
B
49. The isomerization of cyclopropane to propylene is a first-order process with a half-life of 19 minutes at 500 °C. The time it takes for the partial pressure of cyclopropane to decrease from 1.0 atmosphere to 0.125 atmosphere at 500 °C is closest to (A) 38 minutes (B) 57 minutes (C) 76 minutes (D) 152 minutes (E) 190 minutes
B
52. Propane gas, C3H8, burns in excess oxygen gas. When the equation for this reaction is correctly balanced and all coefficients are reduced to their lowest whole-number terms, the coefficient for O2 is (A) 4 (B) 5 (C) 7 (D) 10 (E) 22
B
52. Under which of the following sets of conditions could the most O2(g) be dissolved in H2O(l)? Pressure of O2(g) Temperature of H2O Above H2O(l) (atm) °(C) A) 5.0 80 B) 5.0 20 C) 1.0 80 D) 1.0 20 E) 0.5 20
B
53. Which, if any, of the following species is in the greatest concentration in a 0.100-molar solution of H2SO4 in water? (A) H2SO4 molecules (B) H3O+ ions (C) HSO4¯ ions (D) SO42¯ ions (E) All species are in equilibrium and therefore have the same concentrations.
B
57. For the reaction A(g) <===> B(g) + C(g), the equilibrium constant, Kp, is 2 x 10¯4 at 25 °C. A mixture of the three gases at 25 °C is placed in a reaction flask and the initial pressures are PA = 2 atmosphere, PB = 0.5 atmosphere, and PC = 1 atmosphere, At the instant of mixing, which of the following is true for the reaction as written? (A) DG < 0 (B) DG > 0 (C) DS = 0 (D) DG° = 0 (E) DG° < 0
B
61. A 1-molar solution of which of the following salts has the highest pH ? (A) NaNO3 (B) Na2CO3 (C) NH4Cl (D) NaHSO4 (E) Na2SO4
B
61. When acidified K2Cr2O7 solution is added to Na2S solution, green Cr3+ ions and free S are formed. When acidified K2Cr2O7 solution is added to NaCl, no change occurs. Of the substances involved in these reactions, which is the best reducing agent? (A) K2Cr2O7 (B) Na2S (C) Cr3+ (D) S (E) NaCl
B
63. Mixtures that would be considered buffers include which of the following? I. 0.10 M HCl + 0.10 M NaCl II. 0.10 M HF + 0.10 M NaF III. 0.10 M HBr + 0.10 M NaBr (A) I only (B) II only (C) III only (D) I and II (E) II and III
B
63. What is the maximum mass of copper that could be plated out by electrolyzing aqueous CuCl2 for 16.0 hours at a constant current of 3.00 amperes? (1 faraday = 96,500 coulombs) (A) 28 grams (B) 57 grams (C) 64 grams (D) 114 grams (E) 128 grams
B
67. A student wishes to prepare 2.00 liters of 0.100-molar KIO3 (molecular weight 214). The proper procedure is to weigh out (A) 42.8 grams of KIO3 and add 2.00 kilograms of H2O (B) 42.8 grams of KIO3 and add H2O until the final homogeneous solution has a volume of 2.00 liters (C) 21.4 grams of KIO3 and add H2O until the final homogeneous solution has a volume of 2.00 liters (D) 42.8 grams of KIO3 and add 2.00 liters of H2O (E) 21.4 grams fo KIO3 and add 2.00 liters of H2O
B
67. BrO3¯ + 5 Br¯ + 6 H+ <===> 3 Br2 + 3 H2O If 25.0 milliliters of 0.200-molar BrO3¯ is mixed with 30.0 milliliters of 0.450-molar Br¯ solution that contains a large excess of H+, the amount of Br2 formed, according to the equation above, is (A) 5.00 x 10¯3 mole (B) 8.10 x 10¯3 mole (C) 1.35 x 10¯2 mole (D) 1.50 x 10¯2 mole (E) 1.62 x 10¯2 mole
B
68. A 20.0-milliliter sample of 0.200-molar K2CO3 solution is added to 30.0 milliliters of 0.400-molar Ba(NO3)2 solution. Barium carbonate precipitates. The concentration of barium ion, Ba2+, in solution after reaction is (A) 0.150 M (B) 0.160 M (C) 0.200 M (D) 0.240 M (E) 0.267 M
B
69. What is the mole fraction of ethanol, C2H5OH, in an aqueous solution in which the ethanol concentration is 4.6 molal? (A) 0.0046 (B) 0.076 (C) 0.083 (D) 0.20 (E) 0.72
B
H2(g) + Br2(g) <=> 2 HBr(g) 42. At a certain temperature, the value of the equilibrium constant, K, for the reaction represented above is 2.0105. What is the value of K for the reverse reaction at the same temperature? (A) -2.0 x 10-5 (B) 5.0 x 10-6 (C) 2.0 x 10-5 (D) 5.0 x 10-5 (E) 5.0 x 10-4
B
Look at 63, Need Graph 63. The graph above shows the results of a study of the reaction of X with a large excess of Y to yield Z. The concentrations of X and Y were measured over a period of time. According to the results, which of the following can be concluded about the rate of law for the reaction under the conditions studied? A) It is zero order in [X]. B) It is first order in [X]. C) It is second order in [X]. D) It is the first order in [Y]. E) The overall order of the reaction is 2.
B
Look at Table 36. The initial-rate data in the table above were obtained for the reaction represented below. What is the experimental rate la for the reaction? (A) rate = k[NO] [O2] (B) rate = k[NO] [O2]2 (C) rate = k[NO]2 [O2] (D) rate = k[NO]2 [O2]2 (E) rate = k[NO] / [O2]
B
(A) NH3 and NH4Cl (B) H3PO4 and NaH2PO4 (C) HCl and NaCl (D) NaOH and NH3 (E) NH3 and HC2H3O2 (acetic acid) 9. The solution with the lowest pH
C
14. Which of the following is lower for a 1.0-molar aqueous solution of any solute than it is for pure water? (A) pH (B) Vapor pressure (C) Freezing point (D) Electrical conductivity (E) Absorption of visible light
C
15. The weight of H2SO4 (molecular weight 98.1) in 50.0 milliliters of a 6.00-molar solution is (A) 3.10 grams (B) 12.0 grams (C) 29.4 grams (D) 294 grams (E) 300. grams
C
16. 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
C
17. The Lewis dot structure of which of the following molecules shows only one unshared pair of valence electron? (A) Cl2 (B) N2 (C) NH3 (D) CCl4 (E) H2O2
C
24. 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
C
27. I. Difference in temperature between freezing point of solvent and freezing point of solvent and freezing point of solution II. Molal freezing point depression constant, Kf, for solvent In addition to the information above, which of the following gives the minimum data required to determine the molecular mass of a nonionic substance by the freezing point depression technique? (A) No further information is necessary. (B) Mass of solute (C) Mass of solute and mass of solvent (D) Mass of solute and volume of solvent (E) Mass of solute, mass of solvent, and vapor pressure of solvent
C
30. When 84-Po-214 decays, the emission consists consecutively of an alpha particle, then two beta particles, and finally another alpha particle. The resulting stable nucleus is (A) 83-Bi-206 (B) 83-Bi-210 (C) 82-Pb-206 (D) 82-Pb-208 (E) 81-Tl-210
C
31. H2C2O4 + 2 H2O ---> 2 H3O+ + C2O42¯ Oxalic acid, H2C2O4, is a diprotic acid with K1 = 5.36 x 10¯2 and K2 = 5.3 x 10¯5. For reaction above, what is the equilibrium constant? (A) 5.36 x 10¯2 (B) 5.3 x 10¯5 (C) 2.8 x 10¯6 (D) 1.9 x 10¯10 (E) 1.9 x 10¯13
C
32. A 2.00-liter sample of nitrogen gas at 27 °C and 600. millimeters of mercury is heated until it occupies a volume of 5.00 liters. If the pressure remains unchanged, the final temperature of the gas is (A) 68 °C (B) 120 °C (C) 477 °C (D) 677 °C (E) 950. °C
C
33. A 1.0 L sample of an aqueous solution contains 0.10 mol of NaCl and 0.10 mol of CaCl2. What is the minimum number of moles of AgNO3 that must be added to the solution in order to precipitate all of the Cl¯ as AgCl(s) ? (Assume that AgCl is insoluble.) (A) 0.10 mol (B) 0.20 mol (C) 0.30 mol (D) 0.40 mol (E) 0.60 mol
C
47. CH4(g) + 2 O2(g) ---> CO2(g) + 2 H2O(l); D = - 889.1 kJ DHf° H2O(l) = - 285.8 kJ / mole DHf° CO2(g) = - 393.3 kJ / mole What is the standard heat of formation of methane, DHf° CH4(g), as calculated from the data above? (A) -210.0 kJ/mole (B) -107.5 kJ/mole (C) -75.8 kJ/mole (D) 75.8 kJ/mole (E) 210.0 kJ/mole
C
47. When hafnium metal is heated in an atmosphere of chlorine gas, the product of the reaction is found to contain 62.2 percent Hf by mass and 37.4 percent Cl by mass. What is the empirical formula for this compound? (A) HfCl (B) HfCl2 (C) HfCl3 (D) HfCl4 (E) Hf2Cl3
C
53. Which of the following must be true for a reaction that proceeds spontaneously from initial standard state conditions? (A) G° > 0 and Keq > 1 (B) G° > 0 and Keq < 1 (C) G° < 0 and Keq > 1 (D) G° < 0 and Keq > 1 (E) G° = 0 and Keq = 1
C
55. What volume of 0.150-molar HCl is required to neutralize 25.0 millilters of 0.120-molar Ba(OH)2? (A) 20.0 mL (B) 30 0 mL (C) 40.0 mL (D) 60.0 mL (E) 80.0 mL
C
56. A 0.20-molar solution of a weak monoprotic acid, HA, has a pH of 3.00. The ionization constant of this acid is (A) 5.0 x 10¯7 (B) 2.0 x 10¯7 (C) 5.0 x 10¯6 (D) 5.0 x 10¯3 (E) 2.0 x 10¯3
C
56. A cube of ice is added to some hot water in a rigid, insulated container, which is then sealed. There is no heat exchange with the surroundings. What has happened to the total energy and the total entropy when the system reaches equilibrium? Energy Entropy (A) Remains constant Remains constant (B) Remains constant Decreases (C) Remains constant Increases (D) Decreases Increases (E) Increases Decreases
C
58. (CH3)3CCl(aq) + OH¯ ---> (CH3)3COH(aq) + Cl¯ For the reaction represented above, the experimental rate law is given as follows. Rate = k [(CH3)3CCl] If some solid sodium solid hydroxide is added to a solution that is 0.010-molar in (CH3)3CCl and 0.10-molar in NaOH, which of the following is true? (Assume the temperature and volume remain constant.) (A) Both the reaction rate and k increase. (B) Both the reaction rate and k decrease. (C) Both the reaction rate and k remain the same. (D) The reaction rate increases but k remains the same. (E) The reaction rate decreases but k remains the same.
C
59. A 40.0 mL sample of 0.25 M KOH is added to 60.0 mL of 0.15 M Ba(OH)2. What is the molar concentration of OH¯(aq) in the resulting solution? (Assume that the volumes are additive) A) 0.10 M B) 0.19 M C) 0.28 M D) 0.40 M E) 0.55 M
C
65. 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
C
69. What is the final concentration of barium ions, [Ba2+], in solution when 100. mL of 0.10 M BaCl2(aq) is mixed with 100. mL of 0.050 M H2SO4(aq)? A) 0.00 M B) 0.012 M C) 0.025 M D) 0.075 M E) 0.10 M
C
8-10 Refer to the following diatomic species (A) Li2 (B) B2 (C) N2 (D) O2 (E) F2 10. Contains 1 sigma (s) and 2 pi (p) bonds
C
8-10 Refer to the following diatomic species (A) Li2 (B) B2 (C) N2 (D) O2 (E) F2 8. Has the largest bond-dissociation energy
C
8. Solid ethyl alcohol, C2H5OH (A) A network solid with covalent bonding (B) A molecular solid with zero dipole moment (C) A molecular solid with hydrogen bonding (D) An ionic solid (E) A metallic solid
C
82. Step 1) N2H2O2 <===> N2HO2¯ + H+ (fast equilibrium) Step 2) N2HO2¯ ---> N2O + OH¯ (slow) Step 3) H+ + OH¯ ---> H2O (fast) Nitramide, N2H2O2, decomposes slowly in aqueous solution. This decomposition is believed to occur according to the reaction mechanism above. The rate law for the decomposition of nitramide that is consistent with this mechanism is given by which of the following? (A) Rate = k [N2H2O2] (B) Rate = k [N2H2O2] [H+] (C) Rate = (k [N2H2O2]) / [H+] (D) Rate = (k [N2H2O2]) / [N2HO2¯] (E) Rate = k [N2H2O2] [OH¯]
C
... Cr2O7 2-(aq) + .. . H2S(g) + ... H+(aq) ... Cr3+(aq) + ... S(s) + ... H2O(l) 49. When the equation above is correctly balanced and all coefficients are reduced to lowest whole-number terms, the coefficient for H+(aq) is (A) 2 (B) 4 (C) 6 (D) 8 (E) 14
D
10 HI + 2 KMnO4 + 3 H2SO4 --> 5 I2 + 2 MnSO4 + K2SO4 + 8 H2O 55. According to the balanced equation above, how many moles of HI would be necessary to produce 2.5 mol of I2, starting with 4.0 mol of KMnO4 and 3.0 mol of H2SO4? A) 20 B) 10 C) 8.0 D) 5.0 E) 2.5
D
21. Correct statements about alpha particles include which of the following? I. They have a mass number of 4 and a charge of +2. II. They are more penetrating than beta particles. III. They are helium nuclei. (A) I only (B) III only (C) I and II (D) I and III (E) II and III
D
24. The safest and most effective emergency procedure to treat an acid splash on skin is to do which of the following immediately? (A) Dry the affected area with paper towels (B) Sprinkle the affected area with powdered Na2SO4(s) (C) Flush the affected area with water and then with a dilute NaOH solution (D) Flush the affected area with water and then with a dilute NaHCO3 solution (E) Flush the affected area with water and then with a dilute vinegar solution
D
25. The simplest formula for an oxide of nitrogen that is 36.8 percent nitrogen by weight is (A) N2O (B) NO (C) NO2 (D) N2O3 (E) N2O5
D
32. 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
D
32. Types of hybridization exhibited by the C atoms in propene, CH3CHCH2, include which of the following? I. sp II. sp2 III. sp3 (A) I only (B) III only (C) I and II only (D) II and III only (E) I, II, and III
D
33. The pH of 0.1-molar ammonia is approximately (A) 1 (B) 4 (C) 7 (D) 11 (E) 14
D
36. Appropriate laboratory procedures include which of the following? I. Rinsing a buret with distilled water just before filling it with the titrant for the first titration II. Lubricating glass tubing before inserting it into a stopper III. For accurate results, waiting until warm or hot objects have reached room temperature before weighing them (A) II only (B) I and II only (C) I and III only (D) II and III only (E) I, II, and III
D
40. 2 K + 2 H2O ---> 2 K+ + 2 OH¯ + H2 When 0.400 mole of potassium reacts with excess water at standard temperature and pressure as shown in the equation above, the volume of hydrogen gas produced is (A) 1.12 liters (B) 2.24 liters (C) 3.36 liters (D) 4.48 liters (E) 6.72 liters
D
40. An excess of Mg(s) is added to 100. mL of 0.400 M HCl. At 0˚C and 1 atm pressure, what volume of H2 gas can be obtained? (A) 22.4 mL (B) 44.8 mL (C) 224 mL (D) 448 mL (E) 896 mL
D
42. Mass of an empty container = 3.0 grams Mass of the container plus the solid sample = 25.0 grams Volume of the solid sample = 11.0 cubic centimeters The data above were gathered in order to determine the density of an unknown solid. The density of the sample should be reported as (A) 0.5 g/cm3 (B) 0.50 g/cm3 (C) 2.0 g/cm3 (D) 2.00 g/cm3 (E) 2.27 g/cm3
D
42. The SbCl5 molecule has trigonal bipyramid structure. Therefore, the hybridization of Sb orbitals should be (A) sp2 (B) sp3 (C) dsp2 (D) dsp3 (E) d2sp3
D
43. A sample of 61.8 g of H3BO3, a weak acid is dissolved in 1,000 g of water to make a 1.0-molal solution. Which of the following would be the best procedure to determine to molarity of the solution? (Assume no additional information is available.) (A) Titration of the solution with standard acid (B) Measurement of the pH with a pH meter (C) Determination of the boiling point of the solution (D) Measurement of the total volume of the solution (E) Measurement of the specific heat of the solution
D
44. What number of moles of O2 is needed to produce 14.2 grams of P4O10 from P? (Molecular weight P4O10 = 284) (A) 0.0500 mole (B) 0.0625 mole (C) 0.125 mole (D) 0.250 mole (E) 0.500 mole
D
45. What is the H+(aq) concentration in 0.05 M HCN (aq) ? (The Ka for HCN is 5.0 x 10¯10) (A) 2.5 x 10¯11 (B) 2.5 x 10¯10 (C) 5.0 x 10¯10 (D) 5.0 x 10¯6 (E) 5.0 x 10¯4
D
47. Which of the following has the lowest conductivity? (A) 0.1 M CuS04 (B) 0.1 M KOH (C) 0.1 M BaCl2 (D) 0.1 M HF (E) 0.1 M HNO3
D
5. Represents an atom that is chemically unreactive
D
51. 4 HCl(g) + O2(g) <===> 2 Cl2(g) + 2 H2O(g) Equal numbers of moles of HCl and O2 in a closed system are allowed to reach equilibrium as represented by the equation above. Which of the following must be true at equilibrium? I. [HCl] must be less than [Cl2]. II. [O2] must be greater than [HCl]. III. [Cl2] must equal [H2O]. (A) I only (B) II only (C) I and III only (D) II and III only (E) I, II, and III
D
55. At 20. °C, the vapor pressure of toluene is 22 millimeters of mercury and that of benzene is 75 millimeters of mercury. An ideal solution, equimolar in toluene and benzene, is prepared. At 20. °C, what is the mole fraction of benzene in the vapor in equilibrium with this solution? (A) 0.23 (B) 0.29 (C) 0.50 (D) 0.77 (E) 0.83
D
59. When 70. milliliter of 3.0-molar Na2CO3 is added to 30. milliliters of 1.0-molar NaHCO3 the resulting concentration of Na+ is (A) 2.0 M (B) 2.4 M (C) 4.0 M (D) 4.5 M (E) 7.0 M
D
61. When a solution of potassium dichromate is added to an acidified solution of iron(II) sulfate, the products of the reaction are (A) FeCr2O7(s) and H2O (B) FeCrO4(s) and H2O (C) Fe3+, CrO42¯, and H2O (D) Fe3+, Cr3+, and H2O (E) Fe2(SO4)3(s), Cr3+ and H2O
D
62. A student pipetted five 25.00-milliliter samples of hydrochloric acid and transferred each sample to an Erlenmeyer flask, diluted it with distilled water, and added a few drops of phenolphthalein to each. Each sample was then titrated with a sodium hydroxide solution to the appearance of the first permanent faint pink color. The following results were obtained. Volumes of NaOH Solution First Sample..................35.22 mL Second Sample..............36.14 mL Third Sample.................36.13 mL Fourth Sample..............36.15 mL Fifth Sample..................36.12 mL Which of the following is the most probable explanation for the variation in the student's results? (A) The burette was not rinsed with NaOH solution. (B) The student misread a 5 for a 6 on the burette when the first sample was titrated. (C) A different amount of water was added to the first sample. (D) The pipette was not rinsed with the HCI solution. (E) The student added too little indicator to the first sample.
D
66. MnS(s) + 2 H+ <===> 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 (D) 5 x 10¯15 / 1 x 10¯20 (E) 1 x 10¯20 / 5 x 10¯15
D
66. What is the pH of a 1.0 x 10¯2-molar solution of HCN? (For HCN, Ka = 4.0 x 10¯10.) (A) 10 (B) Between 7 and 10 (C) 7 (D) Between 4 and 7 (E) 4
D
73. The volume of distilled water that should be added to 10.0 mL of 6.00 M HCl(aq) in order to prepare a 0.500 M HCl(aq) solution is approximately A) 50.0 mL B) 60.0 mL C) 100. mL D) 110. mL E) 120. mL
D
74. 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
D
Rate = k[M][N]2 57. The rate of a certain chemical reaction between substances M and N obeys the rate law above. The reaction is first studied with [M] and [N] each 1 x 10^-3 molar. If a new experiment is conducted with [M] and [N] each 2 x 10^-3 molar, the reaction rate will increase by a factor of (A) 2 (B) 4 (C) 6 (D) 8 (E) 16
D
(A) NH3 and NH4Cl (B) H3PO4 and NaH2PO4 (C) HCl and NaCl (D) NaOH and NH3 (E) NH3 and HC2H3O2 (acetic acid) 10. The most nearly neutral solution
E
(A) O (B) La (C) Rb (D) Mg (E) N 2. Which element exhibits the greatest number of different oxidation states?
E
(A) hydrogen bonding (B) hybridization (C) ionic bonding (D) resonance (E) van der Waals forces (London dispersion forces) 11. Is used to explain why iodine molecules are held together in the solid state
E
15. In a molecule in which the central atom exhibits sp3d2 hybrid orbitals, the electron pairs are directed toward the corners of (A) a tetrahedron (B) a square-based pyramid (C) a trigonal bipyramid (D) a square (E) an octahedron
E
17. Is a gas in its standard state at 298 K (A) Lithium (B) Nickel (C) Bromine (D) Uranium (E) Fluorine
E
19. In which of the following species does sulfur have the same oxidation number as it does in H2SO4? (A) H2SO3 (B) (S2O3)2- (C) (S)2- (D) S8 (E) SO2Cl2
E
2 SO3 (g) <===> 2 SO2 (g) + O2 (g) 41. After the equilibrium represented above is established, some pure O2 (g) is injected into the reaction vessel at constant temperature. After equilibrium is reestablished, which of the following has a lower value cmpared to its value at the original equilibrium? (A) Keq for the reaction (B) The total pressure in the reaction vessel. (C) The amount of SO3 (g) in the reaction vessel. (D) The amount of O2 (g) in the reaction vessel. (E) The amount of SO2 (g) in the reaction vessel.
E
20. .....Mg(s) + .....NO3¯(aq) +.....H+(aq) --->......Mg2+(aq) + ....NH4+(aq) + ....H2O(l) When the skeleton equation above is balanced and all coefficients reduced to their lowest whole-number terms. what is the coeficient for H+ ? (A) 4 (B) 6 (C) 8 (D) 9 (E) 10
E
20. A flask contains 0.25 mole of SO2(g), 0.50 mole of CH4(g), and 0.50 mole of O2(g). The total pressure of the gases in the flask is 800 mm Hg. What is the partial pressure of the SO2(g) in the flask? (A) 800 mm Hg (B) 600 mm Hg (C) 250 mm Hg (D) 200 mm Hg (E) 160 mm Hg
E
22. 1s2 2s22p6 3s23p3 Atoms of an element, X, have the electronic configuration shown above. The compound most likely formed with magnesium, Mg, is (A) MgX (B) Mg2X (C) MgX2 (D) MgX3 (E) Mg3X2
E
22. HSO4¯ + H2O <===> H3O+ + SO42¯ In the equilibrium represented above, the species that act as bases include which of the following? I. HSO4¯ II. H2O III. SO42¯ (A) II only (B) III only (C) I and II (D) I and III (E) II and III
E
23. How many grams of calcium nitrate, Ca(NO3)2, contains 24 grams of oxygen atoms? (A) 164 grams (B) 96 grams (C) 62 grams (D) 50. grams (E) 41 grams
E
31. A 0.1-molar solution of which of the following ions is orange? (A) Fe(H2O)42+ (B) Cu(NH3)42+ (C) Zn(OH)42¯ (D) Zn(NH3)42+ (E) Cr2O72¯
E
44. The metal calcium reacts with molecular hydrogen to form a compound. All of the following statements concerning this compound are true EXCEPT: (A) Its formula is CaH2. (B) It is ionic. (C) It is solid at room temperatur(E) (D) When added to water, it reacts to produce H2 gas. (E) When added to water, it forms an acidic solution.
E
44. Which of the following solutions has the lowest freezing point? (A) 0.20 m C6H12O6, glucose (B) 0.20 m NH4Br (C) 0.20 m ZnSO4 (D) 0.20 m KMnO4 (E) 0.20 m MgCl2
E
46. Which of the following solids dissolves in water to form a colorless solution? (A) CrCl3 (B) FeCl3 (C) CoCl2 (D) CuCl2 (E) ZnCl2
E
48. Which of the following ions is the strongest Lewis acid? (A) Na+ (B) Cl¯ (C) CH3COO¯ (D) Mg2+ (E) Al3+
E
50. Which of the following acids can be oxidized to form a stronger acid? (A) H3PO4 (B) HNO3 (C) H2CO3 (D) H3BO3 (E) H2SO3
E
59. Which of the following compounds is ionic and contains both sigma and pi covalent bonds? (A) Fe(OH)3 (B) HClO (C) H2S (D) NO2 (E) NaCN
E
64. The net ionic equation for the reaction that occurs during the titration of nitrous aicd with sodium hydroxide is (A) HNO2 + Na+ + OH¯ ---> NaNO2 + H2O (B) HNO2 + NaOH ---> Na+ + NO2¯ + H2O (C) H+ + OH¯ --->H2O (D) HNO2 + H2O ---> NO2¯ + H3O+ (E) HNO2 + OH¯ ---> NO2¯ + H2O
E
67. 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 D) (4 x 10¯12 M)1/3 E) (2 x 10¯12 M)1/3
E
68. The specific rate constant k for radioactive element X is 0.023 min -1. What weight of X wsa originally present in a sample if 40. grams is left after 60. minutes? (A) 10. grams (B) 20. grams (C) 80. grams (D) 120 grams (E) 160 grams
E
71. A solution of toluene (molecular weight 92.1) in benzene (molecular weight 78.1) is prepared. The mole fraction of toluene in the solution is 0.100. What is the molality of the solution? (A) 0.100 m (B) 0.703 m (C) 0.921 m (D) 1.28 m (E) 1.42 m
E
71. Which of the following reactions does NOT proceed significantly to the right in aqueous solutions? (A) H3O+ + OH¯ ---> 2 H2O (B) HCN + OH¯ ---> H2O + CN¯ (C) Cu(H2O)42+ + 4 NH3 ---> Cu(NH3)42+ + 4H2O (D) H2SO4 + H2O ---> H3O+ + HSO4¯ (E) H2O + HSO4¯ ---> H2SO4 + OH¯
E
72. The nuclide 245Cm is radioactive and decays by the loss of one beta ([beta]¯) particle. The product nuclide is (A) 245Pu (B) 95Am (C) 248Cm (D) 250Cm (E) 97Bk
E
79. 5 Fe2+ + MnO4¯ + 8 H+ <===> 5 Fe3+ + Mn2+ + 4 H2O In a titration experiment based on the equation above, 25.0 milliliters of an acidified Fe2+ solution requires 14.0 milliliters of standard 0.050-molar MnO4¯ solution to reach the equivalence point. The concentration of Fe2+ in the original soluiton is (A) 0.0010 M (B) 0.0056 M (C) 0.028 M (D) 0.090 M (E) 0.14 M
E
Hydrogen Halide Normal Boiling Point, °C HF +19 HCl - 85 HBr - 67 HI - 35 The liquefied hydrogen halides have the normal boiling points given above. The relatively high boiling point of HF can be correctly explained by which of the followng? (A) HF gas is more ideal. (B) HF is the strongest acid. (C) HF molecules have a smaller dipole moment. (D) HF is much less soluble in water. (E) HF molecules tend to form hydrogen bonds.
E