Concept Questions
72) A solution contains 2.2 × 10-3 M in Cu2+ and 0.33 M in LiCN. If the Kf for Cu(CN)42- is 1.0 × 1025, how much copper ion remains at equilibrium? A) 3.8 × 10-24 M B) 1.9 x 10-26 M C) 6.7 × 10-28 M D) 2.9 × 10-27 M E) 4.6 × 10-25 M
B
75) Which of the following is a Lewis base? A) AlF3 B) H2O C) SiF4 D) C5H12 E) None of the above are Lewis bases.
B
24) For a given compound, list the decreasing order of entropy for a liquid, solid, and gas A) solid > gas > liquid B) liquid > solid > gas C) gas > liquid > solid D) gas > solid > liquid E) solid > liquid > gas
C
24) When titrating a weak monoprotic acid with NaOH at 25°C, the A) pH will be less than 7 at the equivalence point. B) pH will be equal to 7 at the equivalence point. C) pH will be greater than 7 at the equivalence point. D) titration will require more moles of base than acid to reach the equivalence point. E) titration will require more moles of acid than base to reach the equivalence point.
C
79) A sample contains Ba3(PO4)2, CdS, AgCl, NH4Cl, and ZnS. Identify the precipitate after the addition of 6 M HCl. A) Ca3(PO4)2 B) HgS C) AgCl D) NH4Cl E) NiS
C
87) Gives what happens at neutral pH for aluminum hydroxide. A) Al(H2O)63+ precipitates B) Al(H2O)2(OH)4- dissolves C) Al(OH)3 precipitates D) Al precipitates E) Al dissolves
C
9) Place the following in order of increasing molar entropy at 298 K. CO2 C9H20 CO A) CO2 < C9H20 < CO B) C9H20 < CO2 < CO C) CO < CO2 < C9H20 D) C9H20 < CO < CO2 E) CO2 < CO < C9H20
C
9) The stronger the acid, then which of the following is TRUE? A) The stronger the conjugate acid. B) The stronger the conjugate base. C) The weaker the conjugate base. D) The weaker the conjugate acid. E) None of the above.
C
9) Which Br∅nsted-Lowry acid is not considered to be a strong acid in water? A) HI B) HBr C) H2SO3 D) H NO3
C
46) List an ingredient that is in antacid. A) Al(OH)3 B) Mg(OH)2 C) CaCO3 D) all of the above E) none of the above
D
54) Determine the pH of a solution that is 0.15 M HClO2 (Ka = 1.1 x 10-2) and 0.15 M HClO (Ka = 2.9 × 10-8). A) 4.18 B) 9.82 C) 12.55 D) 1.39 E) 3.55
D
55) Choose the statement below that is TRUE. A) K > 1, ΔG°rxn is positive. B) K < 1, ΔG°rxn is negative. C) ΔG°rxn = 0 at equilibrium. D) ΔGrxn = 0 at equilibrium. E) None of the above statements are true.
D
56) Identify the strongest acid. A) H2O B) H2S C) H2Se D) H2Te E) not enough information is available
D
56) What is true if ln K is negative? A) ΔGorxn is positive and the reaction is spontaneous in the forward direction. B) ΔGorxn is negative and the reaction is spontaneous in the forward direction. C) ΔGorxn is negative and the reaction is spontaneous in the reverse direction. D) ΔGorxn is positive and the reaction is spontaneous in the reverse direction. E) ΔGorxn is zero and the reaction is at equilibrium.
D
62) Which one of the following salts, when dissolved in water, produces the solution with the highest pH? A) RbI B) RbBr C) RbCl D) RbF
D
63) Stalactites and stalagmites form as ________ precipitates out of the water evaporating in underground caves. A) hydrochloric acid B) sodium hydroxide C) sodium chloride D) calcium carbonate E) sodium bicarbonate
D
63) Which one of the following salts, when dissolved in water, produces the solution with a pH closest to 7.00? A) NH4Br B) Ca O C) K HSO4 D) CsI
D
64) Which one of the following salts, when dissolved in water, produces the solution with the lowest pH? A) NaCl B) KCl C) MgCl2 D) AlCl3
D
53) Determine the pH of a 0.18 M H2CO3 solution. Carbonic acid is a diprotic acid whose Ka1 = 4.3 × 10-7 and Ka2 = 5.6 × 10-11. A) 11.00 B) 10.44 C) 5.50 D) 4.31 E) 3.56
E
58) What is true if ln K is zero? A) ΔGorxn is positive and the reaction is spontaneous in the forward direction. B) ΔGorxn is negative and the reaction is spontaneous in the forward direction. C) ΔGorxn is negative and the reaction is spontaneous in the reverse direction. D) ΔGorxn is positive and the reaction is spontaneous in the reverse direction. E) ΔGorxn is zero and the reaction is at equilibrium.
E
6) A 100.0 mL sample of 0.20 M HF is titrated with 0.10 M KOH. Determine the pH of the solution after the addition of 200.0 mL of KOH. The Ka of HF is 3.5 × 10-4. A) 9.62 B) 7.00 C) 3.46 D) 10.54 E) 8.14
E
6) Identify the weak diprotic acid. A) CH3COOH B) HCOOH C) H3PO4 D) H2SO4 E) H2CO3
E
72) Give the expression for the solubility product constant for Ca3(PO4)2. A) B) C) D) [ Ca2+]2[ PO43-]3 E) [Ca2+]3[PO43-]2
E
8) Give the characteristics of a strong acid. A) ionizes completely in aqueous solutions B) has equilibrium far to the right C) has a polar bond D) has a weaker bond to hydrogen E) all of the above
E
81) A sample contains Ba3(PO4)2, CdS, AgCl, NH4Cl, and ZnS. Identify the precipitate after the addition of 6 M HCl; H2S and 0.2 M HCl; and OH- to a pH of 8. A) Ba3(PO4)2 B) HgS C) AgCl D) NH4Cl E) MnS
E
8) What is the sign of ΔSuniv for a biological system? A) positive B) negative C) zero D) It depends on the biological system.
A
82) A sample contains Ba3(PO4)2, CdS, AgCl, NH4Cl, and ZnS. Identify the precipitate after the addition of 6 M HCl; H2S and 0.2 M HCl; OH- to a pH of 8; and (NH4)2HPO4 with NH3. A) Ca3(PO4)2 B) HgS C) AgCl D) NH4Cl E) ZnS
A
85) Describe the solubility of Al(OH)3 with respect to pH. A) soluble at low pH, insoluble in pH-neutral solution, and soluble at high pH B) soluble at low pH, insoluble in pH-neutral solution, and insoluble at high pH C) insoluble at low pH,insoluble in pH-neutral solution, and soluble at high pH D) insolubleinsoluble at low pH, in pH-neutral solution, and at high pH E) pH has no effect on the solubility
A
86) Gives what happens at low pH for aluminum hydroxide. A) Al(H2O)63+ dissolves B) Al(H2O)4(OH)2- precipitates C) Al(OH)3 precipitates D) Al precipitates E) Al dissolves
A
9) Which of the following relationships is correct at constant T and P? A) ΔG is proportional to -ΔSuniv B) ΔG > 0 represents a spontaneous process C) ΔG > 0 represents an increase in kinetic energy D) ΔG < 0 represents a nonspontaneous process E) All of the above are correct
A
13) Identify the triprotic acid. A) HNO3 B) H3PO4 C) H2CO3 D) HFO4 E) H2SO4
B
13) Which of the following solutions would have the highest pH? Assume that they are all 0.10 M in acid at 25∘C. The acid is followed by its Ka value. A) HF, 3.5 × 10-4 B) HCN, 4.9 × 10-10 C) HNO2, 4.6 × 10-4 D) HCHO2, 1.8 × 10-4 E) HClO2, 1.1 × 10-2
B
17) For the following example, identify the following. 3O2(g) → 2O3(g) A) a negative ΔH and a negative ΔS B) a positive ΔH and a negative ΔS C) a negative ΔH and a positive ΔS D) a positive ΔH and a positive ΔS E) It is not possible to determine without more information.
B
17) Identify the compound with the standard free energy of formation equal to zero. A) KBr(s) B) H2(g) C) NO(g) D) O3(g) E) It is hard to determine.
B
2) The ________ Law of Thermodynamics states the energy is conserved in chemical processes. A) Zero B) First C) Second D) Third E) Fourth
B
20) Which of the following is TRUE? A) An effective buffer has a [base]/[acid] ratio in the range of 10 - 100. B) A buffer is most resistant to pH change when [acid] = [conjugate base] C) An effective buffer has very small absolute concentrations of acid and conjugate base. D) A buffer can not be destroyed by adding too much strong base. It can only be destroyed by adding too much strong acid. E) None of the above are true.
B
30) Place the following in order of increasing standard molar entropy. H2O(l) H2O(g) H2O(s) A) H2O(g) < H2O(l) < H2O(s) B) H2O(s) < H2O(l) < H2O(g) C) H2O(g) < H2O(s) < H2O(l) D) H2O(l) < H2O(s) < H2O(g) E) H2O(s) < H2O(g) < H2O(l)
B
33) For a given reaction, ΔH = +35.5 kJ/mol and ΔS = +83.6 J/Kmol. The reaction is spontaneous ________. Assume that ΔH and ΔS do not vary with temperature. A) at T < 425 K B) at T > 425 K C) at all temperatures D) at T > 298 K E) at T < 298 K
B
35) Identify the indicator that has two endpoints. A) phenol red B) alizarin C) crystal violet D) phenolphthalein E) alizarin yellow R
B
38) Which of the following acids is the WEAKEST? The acid is followed by its Ka value. A) HF, 3.5 × 10-4 B) HCN, 4.9 × 10-10 C) HNO2, 4.6 × 10-4 D) H COOH, 1.8 × 10-4 E) HClO2, 1.1 × 10-2
B
47) Which one of the following will form a basic solution in water? A) NaC2H3O2 B) LiCN C) KClO2 D) LiBrO E) All of the above will form basic solutions.
B
5) Identify the base that is in Drano. A) KOH B) NaOH C) KHCO3 D) Na2CO3 E) NH3
B
5) Which of the following is NOT a conjugate acid-base pair? A) NH4+/NH3 B) H3O⁺/OH⁻ C) H2SO3/HSO3⁻ D) C2H3O2⁻/HC2H3O2 E) All of the above are conjugate acid-base pairs.
B
57) What is true if ln K is positive? A) ΔGorxn is positive and the reaction is spontaneous in the forward direction. B) ΔGorxn is negative and the reaction is spontaneous in the forward direction. C) ΔGorxn is negative and the reaction is spontaneous in the reverse direction. D) ΔGorxn is positive and the reaction is spontaneous in the reverse direction. E) ΔGorxn is zero and the reaction is at equilibrium.
B
59) Which of the following reactions will have the largest equilibrium constant (K) at 298 K? A) CaCO3(s) → CaO(s) + CO2(g) ΔG° =+131.1 kJ B) 2 Hg(g) + O2(g) → 2 HgO(s) ΔG° = -180.8 kJ C) 3 O2(g) → 2 O3(g) ΔG° = +326 kJ D) Fe2O3(s) + 3 CO(g) → 2 Fe(s) + 3 CO2(g) ΔG° = -28.0 kJ E) It is not possible to determine without more information.
B
6) Consider the following reaction at constant P. Use the information here to determine the value of ΔSsurr at 298 K. Predict whether or not this reaction will be spontaneous at this temperature. N2(g) + 2 O2(g) → 2 NO2(g) ΔH = +66.4 kJ A) ΔSsurr = +223 J/K, reaction is spontaneous spontaneous B) ΔSsurr = -223 J/K, reaction is not spontaneous C) ΔSsurr = -66.4 J/K, reaction is not spontaneous D) ΔSsurr = +2656 kJ/K, reaction is not spontaneous E) ΔSsurr = -66.4 J/K, it is not possible to predict the spontaneity of this reaction without more information.
B
6) If the pKa of HCHO2 is 3.74 and the pH of an HCHO2/NaCHO2 solution is 3.74, which of the following is TRUE? A) [HCHO2] > [NaCHO2] B) [HCHO2] = [NaCHO2] C) [HCHO2] < [NaCHO2] D) [HCHO2] < <[NaCHO2] E) It is not possible to make a buffer of this pH from HCHO2 and NaCHO2.
B
61) If an equal number of moles of the weak acid HCN and the strong base KOH are added to water, is the resulting solution acidic, basic, or neutral? A) acidic B) basic C) neutral D) There is insufficient information provided to answer this question.
B
64) Give the equation for an unsaturated solution in comparing Q with Ksp. A) Q > Ksp B) Q < Ksp C) Q = Ksp D) Q ≠ Ksp E) none of the above
B
64) Which of the following compounds will have the highest molar solubility in pure water? A) PbSO4, Ksp = 1.82 × 10-8 B) MgCO3, Ksp = 6.82 × 10-6 C) AgCN, Ksp = 5.97 × 10-17 D) PbS, Ksp = 9.04 × 10-29 E) NiS, Ksp = 3.00 × 10-20
B
65) Which of the following compounds will be more soluble in acidic solution than in pure water? A) PbBr2 B) FeS C) Ca(ClO4)2 D) CuI E) None of the above will be more soluble in acidic solution.
B
66) Which of the following is a polyprotic acid? A) HI B) H2SO4 C) HCN D) CCl4 E) HC2H3O2
B
68) Calculate the pH of a 0.080 M carbonic acid solution, H2CO3(aq), that has the stepwise dissociation constants Ka1 = 4.3 × 10-7 and Ka2 = 5.6 × 10-11. A) 1.10 B) 3.73 C) 6.37 D) 10.25
B
7) Which of the following statements is TRUE? A) Entropy is not a state function. B) Endothermic processes decrease the entropy of the surroundings, at constant T and P. C) Endothermic processes are never spontaneous. D) Exothermic processes are always spontaneous. E) None of the above are true.
B
71) A solution contains 0.036 M Cu2+ and 0.044 M Fe2+. A solution containing sulfide ions is added to selectively precipitate one of the metal ions from solution. At what concentration of sulfide ion will a precipitate begin to form? What is the identity of the precipitate? Ksp(CuS) = 1.3 × 10-36, Ksp(FeS) = 6.3 × 10-18. A) 1.4 × 10-16 M, FeS B) 3.6 × 10-35 M, CuS C) 3.6 × 10-35 M, FeS D) 1.4 × 10-16 M, CuS E) No precipitate will form at any concentration of sulfide ion.
B
11) Place the following in order of decreasing standard molar entropy. NaF(s) Li3PO4(aq) NaF(aq) A) NaF(s) > NaF(aq) > Li3PO4(aq) B) NaF(aq) > NaF(s) > Li3PO4(aq) C) Li3PO4(aq) > NaF(aq) > NaF(s) D) NaF(s) > Li3PO4(aq) > NaF(aq) E) NaF(aq) > Li3PO4(aq) > NaF(s)
C
11) Which of the following is a Br∅nsted-Lowry base? A) CBr4 B) HCN C) NH3 D) Cl2 E) None of the above are Br∅nsted-Lowry bases.
C
13) Consider a reaction that has a positive ΔH and a negative ΔS. Which of the following statements is TRUE? A) This reaction will be spontaneous only at high temperatures. B) This reaction will be spontaneous at all temperatures. C) This reaction will be nonspontaneous at all temperatures. D) This reaction will be nonspontaneous only at high temperatures. E) It is not possible to determine without more information.
C
14) Which of the following is TRUE? A) A neutral solution contains [H2O] = [H3O⁺] B) An neutral solution does not contain any H3O+ or OH- C) An acidic solution has [H3O⁺] > [OH⁻] D) A basic solution does not contain H3O+ E) None of the above are true.
C
14) Which of the following is a STRONG acid? A) C6H5CO2H B) HCN C) HClO4 D) NH4+ E) H2O
C
16) For the following example, identify the following. 2 N2O(g) → 2 N2(g) + O2(g) A) a negative ΔH and a negative ΔS B) a positive ΔH and a negative ΔS C) a negative ΔH and a positive ΔS D) a positive ΔH and a positive ΔS E) It is not possible to determine without more information.
C
16) How many of the following are WEAK acids? HNO2 HF HNO3 H2PO4⁻ A) 0 B) 1 C) 3 D) 4 E) 2
C
17) Identify the food that is NOT acidic. A) beer B) apple C) egg white D) soda E) wine
C
2) An important buffer in the blood is a mixture of ________. A) sodium chloride and hydrochloric acid B) hydrochloric acid and sodium hydroxide C) carbonic acid and bicarbonate ion D) acetic acid and bicarbonate ion E) acetic acid and carbonate ion
C
1) Animals will lick up ethylene glycol (antifreeze) due to its sweet taste. The antidote for ethylene glycol poisioning is the administration of ________. A) ethyl alcohol ( alcoholic drinks) B) isopropyl alcohol (rubbing alcohol) C) mineral oil (laxative) D) vinegar E) sodium bicarbonate (baking soda)
A
1) In which of the following processes does the molecules become more orderly? A) water freezing B) ice melting C) water evaporating D) salt dissolving in water E) dry ice subliming
A
1) Which of the following statements is TRUE? A) There is a "heat tax" for every energy transaction. B) A spontaneous reaction is always a fast reaction. C) The entropy of a system always decreases for a spontaneous process. D) Perpetual motion machines are a possibility in the near future. E) None of the above are true.
A
10) Consider a reaction that has a positive ΔH and a positive ΔS. Which of the following statements is TRUE? A) This reaction will be spontaneous only at high temperatures. B) This reaction will be spontaneous at all temperatures. C) This reaction will be nonspontaneous at all temperatures. D) This reaction will be nonspontaneous only at high temperatures. E) It is not possible to determine without more information.
A
10) Which of the following is a Br∅nsted-Lowry acid? A) NH4+ B) CCl4 C) NH2- D) NH3 E) Br2
A
12) Which one of the following has the highest standard molar entropy, S°, at 25°C? A) I2(g) B) F2(g) C) Br2(l) D) O2(g) E) Cl2(g)
A
14) Which one of the following would be expected to have the lowest standard molar entropy, S°, at 25°C? A) C10H22(s) B) C10H22(l) C) C14H30(s) D) C14 H30OH(l)
A
15) Consider a reaction that has a negative ΔH and a negative ΔS. Which of the following statements is TRUE? A) This reaction will be spontaneous only at low temperatures. B) This reaction will be spontaneous at all temperatures. C) This reaction will be nonspontaneous at all temperatures. D) This reaction will be nonspontaneous only at low temperatures. E) It is not possible to determine without more information.
A
15) Identify the compound with the lowest standard free energy of formation. A) NaCl(s) B) O2(g) C) NO(g) D) O3(g) E) It is hard to determine.
A
18) Calculate the concentration of H3O⁺ in a solution that contains 5.5 × 10-5 M OH⁻ at 25°C. Identify the solution as acidic, basic, or neutral. A) 1.8 × 10-10 M, basic B) 1.8 × 10-10 M, acidic C) 5.5 × 10-10 M, neutral D) 9.2 × 10-1 M, acidic E) 9.2 × 10-1 M, basic
A
19) Calculate the concentration of OH⁻ in a solution that contains 3.9 x 10-4 M H3O⁺ at 25°C. Identify the solution as acidic, basic, or neutral. A) 2.6 × 10-11 M, acidic B) 2.6 × 10-11 M, basic C) 3.9 × 10-4 M, neutral D) 2.7 × 10-2 M, basic E) 2.7 × 10-2 M, acidic
A
19) For the following example, identify the following. H2O(l) → H2O(s) A) a negative ΔH and a negative ΔS B) a positive ΔH and a negative ΔS C) a negative ΔH and a positive ΔS D) a positive ΔH and a positive ΔS E) It is not possible to determine without more information.
A
2) Identify the acid that is in car batteries. A) H2SO4 B) HNO3 C) H2CO3 D) CH3COOH E) HCl
A
2) Identify the change in state that does not have an increase in entropy. A) water freezing B) water boiling C) ice melting D) dry ice subliming E) rubbing alcohol evaporating
A
2) Which of the following solutions is a good buffer system? A) A solution that is 0.10 M HC2H3O2 and 0.10 M LiC2H3O2 B) A solution that is 0.10 M HBr and 0.10 M KC2H3O2 C) A solution that is 0.10 M HI and 0.10 M NH4+ D) A solution that is 0.10 M NaOH and 0.10 M KOH E) None of the above are buffer systems.
A
21) Define buffer capacity. A) Buffer capacity is the amount of acid or base that can be added to a buffer without destroying its effectiveness. B) Buffer capacity is the amount of acid that can be added until all of the base is used up. C) Buffer capacity is the amount of base that can be added until all of the acid is used up. D) Buffer capacity is the amount of acid that can be added until all of the acid is used up. E) Buffer capacity is the amount of base that can be added until all of the base is used up.
A
22) Which of the following is TRUE? A) The equivalence point is where the amount of acid equals the amount of base during any acid-base titration. B) At the equivalence point, the pH is always 7. C) An indicator is not pH sensitive. D) A titration curve is a plot of pH vs. the [base]/[acid] ratio. E) None of the above are true.
A
25) Which of the following statements is TRUE? A) Entropy is an extensive property. B) Entropy is not temperature dependent. C) Exothermic processes decrease the entropy of the surroundings. D) ΔSuniverse is always greater than zero for a nonspontaneous process. E) None of the above are true.
A
3) Identify the process that is spontaneous A) rusting of iron B) electrolysis C) photosynthesis D) bread rising E) burning gasoline
A
31) A 1.0 L buffer solution is 0.050 M HC2H3O2 and 0.250 M NaC2H3O2. Which of the following actions will destroy the buffer? A) adding 0.050 moles of KOH B) adding 0.050 moles of HCl C) adding 0.050 moles of HC2H3O2 D) adding 0.050 moles of NaC2H3O2 E) All of the above will destroy the buffer.
A
31) Place the following in order of decreasing standard molar entropy. N2O4(g) NO(g) NO2(g) A) N2O4 > NO2 > NO B) NO > NO2 > N2O4 C) N2O4 > NO > NO2 D) NO > N2O4 > NO2 E) NO2 > NO > N2O4
A
36) Which of the following bases is the STRONGEST? The base is followed by its Kb. A) (CH3CH2)2NH, 8.6 × 10-4 B) CH3NH2, 4.4 × 10-4 C) C6H5NH2, 4.0 × 10-10 D) NH3, 1.76 × 10-5 E) C5H5N, 1.7 × 10-9
A
39) Give the name of the reaction that achieves the theoretical limits with respect to free energy in thermodynamics. A) reversible reaction B) forward reaction C) reverse reaction D) equilibrium reaction E) irreversible reaction
A
4) What is the conjugate base of H2PO4⁻ ? A) HPO42- B) PO43- C) H3PO4 D) H3O+ E) OH⁻
A
43) A 25.0-mL sample of 0.150 M butanoic acid is titrated with a 0.150 M NaOH solution. What is the pH before any base is added? The Ka of butanoic acid is 1.5 × 10-5. A) 2.83 B) 1.5 × 10-3 C) 4.82 D) 4.00 E) 1.0 × 104
A
44) Which of the following is a STRONG base? A) I- B) NH3 C) CH3OH D) NO3⁻ E) LiOH
A
45) Which of the following is a WEAK base? A) NH(CH3)2 B) N2 C) NaOH D) CH2CI2 E) None of the above are weak bases.
A
5) If the pKa of HCHO2 is 3.74 and the pH of an HCHO2/NaCHO2 solution is 3.89, which of the following is TRUE? A) [HCHO2] < [NaCHO2] B) [HCHO2] = [NaCHO2] C) [HCHO2] > [NaCHO2] D) [HCHO2] >> [NaCHO2] E) It is not possible to make a buffer of this pH from HCHO2 and NaCHO2.
A
5) Which of the following processes shows a decrease in entropy of the system? A) 2 NO(g) + O2(g) → 2 NO2(g) B) COBr2(g) → CO(g) + Br2(g) C) CH3OH(l) → CO(g) + 2H2(g) D) KBrO3(s) →K+(aq) + BrO3-(aq) E) None of the above will show a decrease in entropy.
A
52) In a triprotic acid, which Ka has the highest value? A) Ka1 B) Ka2 C) Ka3 D) Kb1 E) Kb2
A
54) Which of the following is NOT true for ΔGrxn? A) If ΔG°rxn > 0, the reaction is spontaneous in the forward direction. B) If Q = 1, then DGrxn = ΔG°rxn. C) If ΔG°rxn = 0, the reaction is spontaneous in the reverse direction. D) If ΔG°rxn > 0, the reaction is spontaneous in the reverse direction. E) Under equilibrium conditions, ΔGrxn = 0.
A
57) Identify the weakest acid. A) HF B) HCl C) HBr D) HI E) not enough information is available
A
57) The acid-dissociation constant of hydrocyanic acid (HCN) at 25.0°C is 4.9 × 10-10. What is the pH of an aqueous solution of 0.080 M sodium cyanide (NaCN)? A) 11.11 B) 2.89 C) 1.3 × 10-3 D) 7.8 × 10-12 E) 3.9 × 10-11 =
A
58) Acid rain consists primarily of ________. A) nitric and sulfuric acids B) sulfuric acid C) nitric acid D) acetic acid E) benzoic acid
A
6) When dissolved in water, which compound is generally considered to be an Arrhenius acid? A) CH3CO2H B) NaOH C) Na2CO3 D) CH3CH2OH
A
65) Which one of the following will form an acidic solution in water? A) NH4Cl B) KF C) KI D) KNO3 E) None of the above solutions will be acidic.
A
66) Give the equation for a supersaturated solution in comparing Q with Ksp. A) Q > Ksp B) Q < Ksp C) Q = Ksp D) Q ≠ Ksp E) none of the above
A
66) Identify the salts that are in hard water. A) CaCO3 and MgCO3 B) MgSO4 and CaSO4 C) NaCl and KBr D) KHSO4 and Na2SO4 E) NaOCl and HOCl
A
67) Which of the following compounds solubility will not be affected by a low pH in solution? A) AgCl B) Sr(OH)2 C) CaF2 D) CuS E) SrCO3
A
69) Calculate the pH of a 0.60 M H2SO3, solution that has the stepwise dissociation constants Ka1 = 1.5 × 10-2 and Ka2 = 6.3 × 10-8. A) 1.02 B) 1.06 C) 1.82 D) 2.04
A
7) Which of the following is an Arrhenius acid? A) H2SO4 B) LiOH C) NH2CH3 D) CH3CCl3 E) More than one of these is an Arrhenius acid.
A
70) A solution contains 0.021 M Cl⁻ and 0.017 M I⁻. A solution containing copper (I) ions is added to selectively precipitate one of the ions. At what concentration of copper (I) ion will a precipitate begin to form? What is the identity of the precipitate? Ksp(CuCl) = 1.0 × 10-6, Ksp(CuI) = 5.1 × 10-12. A) 3.0 × 10-10 M, CuI B) 3.0 × 10-10 M, CuCl C) 4.8 × 10-5 M, CuCl D) 4.8 × 10-5 M, CuI E) No precipitate will form at any concentration of copper (I).
A
70) Calculate the concentration of bicarbonate ion, HCO3-, in a 0.010 M H2CO3 solution that has the stepwise dissociation constants Ka1 = 4.3 × 10-7 and Ka2 = 5.6 × 10-11. A) 6.6 × 10-5 M B) 4.3 × 10-7 M C) 4.3 × 10-9 M D) 5.6 × 10-11 M
A
71) What is the pH of a 0.40 M H2Se solution that has the stepwise dissociation constants Ka1 = 1.3 × 10-4 and Ka2 = 1.0 × 10-11? A) 2.14 B) 3.89 C) 4.28 D) 5.57
A
73) Give the expression for the solubility product constant for Cr2(CO3)3. A) [Cr3+]2[CO32-]3 B) C) D) E) [3Cr3+]3[2CO32-]2
A
73) Identify the strongest acid. A) HFO4 B) HFO3 C) HFO2 D) HFO E) Not enough information is given.
A
74) Which of the following is a Lewis acid? A) BBr3 B) CCl4 C) NH3 D) CHBr3 E) None of the above are Lewis acids.
A
1) Which of the following solutions is a good buffer system? A) A solution that is 0.10 M NaCl and 0.10 M HCl B) A solution that is 0.10 M HCN and 0.10 M LiCN C) A solution that is 0.10 M NaOH and 0.10 M HNO3 D) A solution that is 0.10 M HNO3 and 0.10 M NaNO3 E) A solution that is 0.10 M HCN and 0.10 M KI
B
1) ________ is found in carbonated beverages due to the reaction of carbon dioxide with water. A) CH3COOH B) H2CO3 C) HCOOH D) C6H5COOH E) CH3CH2COOH
B
10) Place the following in order of increasing acid strength. HBrO2 HBrO3 HBrO HBrO4 A) HBrO2 < HBrO4 < HBrO < HBrO3 B) HBrO < HBrO2 < HBrO3 < HBrO4 C) HBrO2 < HBrO3 < HBrO4 < HBrO D) HBrO4 < HBrO2 < HBrO3 < HBrO E) HBrO < HBrO4 < HBrO3 < HBrO2
B
12) Consider a reaction that has a negative ΔH and a positive ΔS. Which of the following statements is TRUE? A) This reaction will be spontaneous only at high temperatures. B) This reaction will be spontaneous at all temperatures. C) This reaction will be nonspontaneous at all temperatures. D) This reaction will be nonspontaneous only at high temperatures. E) It is not possible to determine without more information.
B
13) Identify the compound that is NOT an allotrope of carbon. A) diamond B) ethanol C) graphite D) charcoal E) buckyball
B
76) A solution of NaF is added dropwise to a solution that is 0.0144 M in Ba2+. When the concentration of F- exceeds ________ M, BaF2 will precipitate. Neglect volume changes. For BaF2, Ksp = 1.7 × 10-6. A) 5.9 × 10-5 B) 1.1 × 10-2 C) 2.4 × 10-8 D) 2.7 × 10-3 E) 1.2 × 10-4
B
77) Identify the compound that is acid-insoluble. A) PbCl2 B) As2S3 C) NiS D) Ca3(PO4)2 E) LiCl
B
8) Which of the following is an Arrhenius base? A) CH3CO2H B) LiOH C) CH3OH D) NaBr E) More than one of these compounds is an Arrhenius base.
B
80) A sample contains Ba3(PO4)2, CdS, AgCl, NH4Cl, and ZnS. Identify the precipitate after the addition of 6 M HCl, then H2S and 0.2 M HCl. A) Ba3(PO4)2 B) CuS C) AgCl D) NH4Cl E) MnS
B
88) Gives what happens at high pH for aluminum hydroxide. A) Al(H2O)33+ precipitates B) Al(H2O)2(OH)4- dissolves C) Al(OH)5 dissolves D) Al precipitates E) Al dissolves
B
26) Identify the statement that is FALSE. A) The entropy of a gas is greater than the entropy of a liquid. B) Entropy generally increases with increasing molecular complexity. C) Free atoms have greater entropy than molecules. D) Entropy increases with dissolution. E) For noble gasses, entropy increases with size.
C
28) Which of the following acids (listed with pKa values) and their conjugate base would form a buffer with a pH of 8.10? A) HC2H3O2, pKa = 4.74 B) H2SO3, pKa = 1.77 C) HClO, pKa = 7.54 D) HIO, pKa = 10.64 E) HNO2, pKa = 3.34
C
29) What is the hydroxide ion concentration and the pH for a hydrochloric acid solution that has a hydronium ion concentration of 1.50 × 10-2 M? A) 6.67 × 10-12 M, 2.82 B) 6.67 × 10-12 M, 11.18 C) 6.67 × 10-13 M, 1.82 D) 6.67 × 10-13 M, 12.17
C
3) Which one of the following statements is TRUE? A) A buffer is an aqueous solution composed of two weak acids. B) A buffer can absorb an unlimited amount of base. C) A buffer resists pH change by neutralizing added acids and bases. D) A buffer does not change pH when strong acid is added. E) None of the above are true.
C
30) A 1.0 L buffer solution is 0.250 M HC2H3O2 and 0.050 M LiC2H3O2. Which of the following actions will destroy the buffer? A) adding 0.050 moles of LiC2H3O2 B) adding 0.050 moles of HC2H3O2 C) adding 0.050 moles of HCl D) adding 0.050 moles of NaOH E) None of the above will destroy the buffer.
C
32) Identify the pH of normal blood. A) 6.9 B) 7.2 C) 7.4 D) 7.6 E) 7.8
C
33) Find the percent ionization of a 0.337 M HF solution. The Ka for HF is 3.5 × 10-4. A) 1.1 % B) 1.2 × 10-2 % C) 3.2 % D) 3.5 × 10-2 % E) 4.7 %
C
34) Identify the indicator that can be used at the lowest pH. A) phenol red B) thymol blue C) crystal violet D) phenolphthalein E) m-nitrophenol
C
37) Which of the following bases is the WEAKEST? The base is followed by its Kb value. A) HOCH2CH2NH2, 3.2 × 10-5 B) NH3, 1.76 × 10-5 C) C5H5N, 1.7 × 10-9 D) (CH3CH2)3N, 5.2 × 10-4 E) Since these are all weak bases, they have the same strength.
C
4) Identify the base that is in baking soda. A) RbOH B) NaOH C) NaHCO3 D) Li2CO3 E) NH3
C
4) ________ is a thermodynamic function that increases with the number of energetically equivalent ways to arrange components of a system to achieve a particular state. A) Heat of reaction B) Free energy C) Entropy D) Enthalpy E) Molar equivalence
C
42) Calculate the pH of a 0.800 M NaCH3CO2 solution. Ka for acetic acid, CH3CO2H, is 1.8 × 10-5. A) 2.42 B) 4.68 C) 9.32 D) 11.58
C
5) A solution is prepared by dissolving 0.23 mol of chloroacetic acid and 0.27 mol of sodium chloroacetate in water sufficient to yield 1.00 L of solution. The addition of 0.05 mol of HCl to this buffer solution causes the pH to drop slightly. The pH does not decrease drastically because the HCl reacts with the __________ present in the buffer solution. The Ka of chloroacetic acid is 1.36 × 10-3. A) H2O B) H3O+ C) chloroacetate ion D) chloroacetic acid E) This is a buffer solution: the pH does not change upon addition of acid or base.
C
5) The ________ Law of Thermodynamics states that for any spontaneous reaction, the entropy of the universe increases. A) Zero B) First C) Second D) Third E) Fourth
C
54) What is the pH of a 0.100 M NH3 solution that has Kb = 1.8 × 10-5? The equation for the dissociation of NH3 is NH3(aq) + H2O(l) ⇌ NH4+(aq) + OH-(aq). A) 1.87 B) 2.87 C) 11.13 D) 10.13
C
55) Determine the concentration of CO32- ions in a 0.18 M H2CO3 solution. Carbonic acid is a diprotic acid whose Ka1 = 4.3 × 10-7 and Ka2 = 5.6 × 10-11. A) 2.8 × 10-4 M B) 3.2 × 10-6 M C) 5.6 × 10-11 M D) 4.3 × 10-7 M E) 6.9 × 10-8 M
C
59) The base-dissociation constant of ethylamine (C2H5NH2) is 6.4 × 10-4 at 25.0°C. The [H+] in a 1.6 × 10-2 M solution of ethylamine is ________ M. A) 3.5 × 10-12 B) 2.9 × 10-3 C) 3.1 × 10-12 D) 3.2 × 10-3 E) 11.46
C
6) Which of the following processes have a ΔS > 0? A) CH3OH(l) → CH3OH(s) B) N2(g) + 3 H2(g) → 2 NH3(g) C) CH4(g) + H2O(g) → CO(g) + 3 H2(g) D) Na2CO3(s) + H2O(g) + CO2(g) → 2 NaHCO3(s) E) All of the above processes have a DS > 0.
C
60) Which one of the following salts, when dissolved in water, produces the solution with the highest pH? A) KHCO3 B) CsClO4 C) RaO D) CH3CH3NH3Cl
C
65) Give the equation for a saturated solution in comparing Q with Ksp. A) Q > Ksp B) Q < Ksp C) Q = Ksp D) Q ≠ Ksp E) none of the above
C
67) A solution containing AgNO3 is mixed with a solution of NaCl to form a solution that is 0.10 M in AgNO3 and 0.075 M in NaCl. What will happen once these solutions are mixed? Ksp (AgCl) = 1.77 × 10-10. A) Nothing will happen since the molar solubility of AgCl is higher than the solution concentrations. B) Silver chloride will precipitate out of solution, leaving an unsaturated solution of AgCl. C) Silver chloride will precipitate out of solution, leaving a saturated AgCl solution. D) Nothing will happen since NaCl and AgNO3 are both soluble compounds. E) There is not enough information to say anything about this solution.
C
67) Which of the following is a triprotic acid? A) HI B) H2SO4 C) H3PO4 D) CCl4 E) HC2H3O2
C
7) Consider the following reaction at constant P. Use the information here to determine the value of ΔSsurr at 355 K. Predict whether or not this reaction will be spontaneous at this temperature. 2 NO(g) + O2(g) → 2 NO2(g) ΔH = -114 kJ A) ΔSsurr = +114 kJ/K, reaction is spontaneous B) ΔSsurr = +114 kJ/K, reaction is not spontaneous C) ΔSsurr = +321 J/K, reaction is spontaneous D) ΔSsurr = -321 J/K, reaction is spontaneous E) ΔSsurr = +321 J/K, it is not possible to predict the spontaneity of this reaction without more information.
C
7) Identify the weak diprotic acid. A) HNO3 B) H3PO4 C) H2SO3 D) HClO4 E) H2SO4
C
70) Give the expression for the solubility product constant for PbCl2. A) B) C) [Pb2+][Cl⁻]2 D) E) [Pb2+]2[2Cl⁻]
C
73) A solution contains 3.8 × 10-2 M in Al3+ and 0.29 M in NaF. If the Kf for AlF63- is 7 × 1019, how much aluminum ion remains at equilibrium? A) 1.1 × 10-19 M B) 3.1 × 10-22 M C) 9.1 × 10-19 M D) 1.9 × 10-21 M E) 4.4 × 10-20 M
C
74) Which of the following compounds will have the highest molar solubility in pure water? A) HgS, Ksp = 1.6 × 10-54 B) CuS, Ksp = 1.27 × 10-36 C) Fe(OH)3, Ksp = 2.79 × 10-39 D) ZnS, Ksp = 2.0 × 10-25 E) Ag2S, Ksp = 6.0 × 10-51
C
76) List the compound in marble that is destroyed by acid rain. A) NH4OH B) NaHCO3 C) CaCO3 D) KOH E) LiOH
C
78) Identify the compound that is base-insoluble. A) PbCl2 B) As2S3 C) ZnS D) Ca3(PO4)2 E) KCl
C
0) What is the hydronium ion concentration and the pH for an aqueous solution of NH3 that has a hydroxide ion concentration of 2.25 × 10-2 M? A) 4.44 × 10-12 M and 2.65 B) 4.44 × 10-12 M and 11.35 C) 4.44 × 10-13 M and 1.65 D) 4.44 × 10-13 M and 12.35
D
1) The stomach excretes ________ to kill microorganisms and to activate enzymes that break down food. A) CH3COOH B) HF C) LiHCO3 D) HCl E) HNO3
D
10) Place the following in order of decreasing molar entropy at 298 K. HF N2H4 Ar A) Ar > N2H4 > HF B) Ar > HF > N2H4 C) N2H4 > Ar > HF D) N2H4 > HF > Ar E) HF > N2H4 > Ar
D
11) Consider a reaction that has a positive ΔH and a positive ΔS. Which of the following statements is TRUE? A) This reaction will be spontaneous only at low temperatures. B) This reaction will be spontaneous at all temperatures. C) This reaction will be nonspontaneous at all temperatures. D) This reaction will be nonspontaneous only at low temperatures. E) It is not possible to determine without more information.
D
11) Which of the following statements is TRUE? A) A strong acid is composed of a proton and an anion that have a very strong attraction for one another. B) A weak base is composed of a cation and an anion with a very weak attraction between them. C) A strong acid has a strong conjugate base. D) The conjugate base of a very weak acid is stronger than the conjugate base of a strong acid. E) None of the above statements are true.
D
12) Identify the diprotic acid. A) HNO3 B) HI C) CH3COOH D) H2SO4 E) HBrO4
D
12) Which of the following acids will have the strongest conjugate base? A) HCl B) HClO4 C) HNO3 D) HCN E) HI
D
14) Consider a reaction that has a negative ΔH and a negative ΔS. Which of the following statements is TRUE? A) This reaction will be spontaneous only at high temperatures. B) This reaction will be spontaneous at all temperatures. C) This reaction will be nonspontaneous at all temperatures. D) This reaction will be nonspontaneous only at high temperatures. E) It is not possible to determine without more information.
D
15) Which of the following is a WEAK acid? A) HClO4 B) H2SO4 C) HBr D) HCN E) HNO3
D
16) Identify the compound with the highest standard free energy of formation. A) NaCl(s) B) H2(g) C) NO(g) D) O3(g) E) It is hard to determine.
D
18) For the following example, identify the following. H2O(l) → H2O(g) A) a negative ΔH and a negative ΔS B) a positive ΔH and a negative ΔS C) a negative ΔH and a positive ΔS D) a positive ΔH and a positive ΔS E) It is not possible to determine without more information.
D
2) Which of the following species is amphoteric? A) CO32- B) HF C) NH4⁺ D) HPO42- E) None of the above are amphoteric.
D
20) You wish to prepare an HC2H3O2 buffer with a pH of 5.14. If the pKa of is 4.74, what ratio of C2H3O2⁻/HC2H3O2 must you use? A) 0.10 B) 0.40 C) 0.40 D) 2.51 E) 6.0
D
21) A buffer solution is 0.100 M in both HC7H5O2 and KC7H5O2 and has a pH of 4.19. Which of the following pH values would you expect from the addition of a small amount of a dilute solution of a strong base? A) 3.89 B) 3.69 C) 5.79 D) 4.49 E) There is not enough information to determine.
D
23) The ________ Law of Thermodynamics states the entropy of a perfect crystal at absolute zero is zero. A) Zero B) First C) Second D) Third E) Fourth
D
23) When titrating a strong monoprotic acid and KOH at 25°C, the A) pH will be less than 7 at the equivalence point. B) pH will be greater than 7 at the equivalence point. C) titration will require more moles of base than acid to reach the equivalence point. D) pH will be equal to 7 at the equivalence point. E) titration will require more moles of acid than base to reach the equivalence point.
D
3) Identify the acid that is in vinegar. A) H2SO4 B) HNO3 C) Na2CO3 D) CH3COOH E) HF
D
3) Which of the following processes have a ΔS > 0? A) 2 NH3(g) + CO2(g) → NH2CONH2(aq) + H2O(l) B) lithium fluoride forms from its elements C) 2 HF(g) → H2(g) + F2(l) D) potassium iodide dissolves in pure water E) All of the above processes have a DS > 0.
D
33) Identify the most common indicator. A) alizarin B) thymol blue C) crystal violet D) phenolphthalein E) thymolphthalein
D
34) Under which of the following conditions would one mole of He have the highest entropy, S? A) 17°C and 15 L B) 127°C and 15 L C) 17°C and 25 L D) 127°C and 25 L
D
4) A solution is prepared by dissolving 0.23 mol of hydrazoic acid and 0.27 mol of sodium azide in water sufficient to yield 1.00 L of solution.The addition of 0.05 mol of NaOH to this buffer solution causes the pH to increase slightly. The pH does not increase drastically because the NaOH reacts with the ________ present in the buffer solution. The Ka of hydrazoic acid is 1.9 × 10-5. A) H2O B) H3O+ C) azide D) hydrazoic acid E) This is a buffer solution: the pH does not change upon addition of acid or base.
D
4) If the pKa of HCHO2 is 3.74 and the pH of an HCHO2/NaCHO2 solution is 3.11, which of the following is TRUE? A) [HCHO2] < [NaCHO2] B) [HCHO2] = [NaCHO2] C) [HCHO2] << [NaCHO2] D) [HCHO2] > [NaCHO2] E) It is not possible to make a buffer of this pH from HCHO2 and NaCHO2
D
68) A solution containing CaCl2 is mixed with a solution of Li2C2O4 to form a solution that is 2.1 × 10-5 M in calcium ion and 4.75 × 10-5 M in oxalate ion. What will happen once these solutions are mixed? Ksp (CaC2O4) = 2.3 × 10-9. A) A precipitate will form since Q > Ksp for calcium oxalate. B) Nothing will happen since both calcium chloride and lithium oxalate are soluble compounds. C) Nothing will happen since calcium oxalate is extremely soluble. D) Nothing will happen since Ksp > Q for all possible precipitants. E) There is not enough information to determine.
D
69) A solution containing CaCl2 is mixed with a solution of Li2C2O4 to form a solution that is 3.5 × 10-4 M in calcium ion and 2.33 × 10-4 M in oxalate ion. What will happen once these solutions are mixed? Ksp (CaC2O4) = 2.3 × 10-9. A) Nothing will happen since both calcium chloride and lithium oxalate are soluble compounds. B) Nothing will happen Ksp > Q for all possible precipitants. C) A precipitate will form as calcium oxalate is not soluble to any extent. D) A precipitate will form since Q > Ksp for calcium oxalate. E) There is not enough information to determine.
D
71) Give the expression for the solubility product constant for BaF2. A) B) C) [Ba2+]2[ F⁻] D) [Ba2+][F⁻]2 E) [Ba2+][2F⁻]
D
72) What is the selenide ion concentration [Se2-] for a 0.100 M H2Se solution that has the stepwise dissociation constants of Ka1 = 1.3 × 10-4 and Ka2 = 1.0 × 10-11? A) 3.6 × 10-3 M B) 1.3 × 10-4 M C) 1.3 × 10-5 M D) 1.0 × 10-11 M
D
75) 0.10 M potassium chromate is slowly added to a solution containing 0.50 M AgNO3 and 0.50 M Ba(NO3)2. What is the Ag+ concentration when BaCrO4 just starts to precipitate? The Ksp for Ag2CrO4 and BaCrO4 are 1.1 × 10-12 and 1.2 × 10-10, respectively. A) 6.5 × 10-5 M B) 1.3 × 10-4 M C) 3.2 × 10-4 M D) 6.8 × 10-2 M
D
8) Consider the following reaction at constant P. Use the information here to determine the value of ΔSsurr at 398 K. Predict whether or not this reaction will be spontaneous at this temperature. 4 NH3(g) + 3 O2(g) → 2 N2(g) + 6 H2O(g) ΔH = -1267 kJ A) ΔSsurr = +12.67 kJ/K, reaction is spontaneous B) ΔSsurr = -12.67 kJ/K, reaction is spontaneous C) ΔSsurr = +50.4 kJ/K, reaction is not spontaneous D) ΔSsurr = +3.18 kJ/K, reaction is spontaneous E) ΔSsurr = -3.18 kJ/K, it is not possible to predict the spontaneity of this reaction without more information.
D
83) A sample contains Ba3(PO4)2, CdS, AgCl, NH4Cl, and ZnS. Identify the soluble ions after the addition of 6 M HCl; H2S and 0.2 M HCl; OH- to a pH of 8; and (NH4)2HPO4 with NH3. A) Ba3(PO4)2 B) HgS C) AgCl D) NH4Cl E) FeS
D
84) A ligand is a molecule or ion that acts as a A) Lewis acid B) Brønsted-Lowry base C) Arrhenius base D) Lewis base E) conjugate base
D
25) When titrating a monoprotic strong acid with a weak base at 25°C, the A) pH will be 7 at the equivalence point. B) pH will be greater than 7 at the equivalence point. C) titration will require more moles of the base than acid to reach the equivalence point. D) titration will require more moles of acid than base to reach the equivalence point. E) pH will be less than 7 at the equivalence point.
E
27) Place the following in order of increasing entropy at 298 K. Ne Xe He Ar Kr A) He < Kr < Ne < Ar < Xe B) Xe < Kr < Ar < Ne < He C) Ar < He < Ar < Ne < Kr D) Ar < Ne < Xe < Kr < He E) He < Ne < Ar < Kr < Xe
E
28) Place the following in order of increasing molar entropy at 298 K. NO CO SO A) NO < CO < SO B) SO < CO < NO C) SO < NO < CO D) CO < SO < NO E) CO < NO < SO
E
29) Place the following in order of decreasing molar entropy at 298 K. H2 Cl2 F2 A) H2 > Cl2 > F2 B) Cl2 > H2 > F2 C) F2 > Cl2 > H2 D) H2 > F2 > Cl2 E) Cl2 > F2 > H2
E
29) Which of the following acids (listed with Ka values) and their conjugate base would form a buffer with a pH of 2.34? A) C6H5COOH, Ka = 6.5 x 10-5 B) HIO3, Ka = 1.7 x 10-1 C) HClO, Ka = 2.9 x 10-8 D) HF, Ka = 3.5 x 10-4 E) HClO2, Ka = 1.1 x 10-2
E
3) Identify a good buffer. A) small amounts of both a weak acid and its conjugate base B) significant amounts of both a strong acid and a strong base C) small amounts of both a strong acid and a strong base D) significant amounts of both a weak acid and a strong acid E) significant amounts of both a weak acid and its conjugate base
E
3) What is the conjugate acid of HCO3⁻ ? A) H3O+ B) H2O C) CO32- D) OH⁻ E) H2CO3
E
32) Which one of the following has the highest standard molar entropy, S°, at 25°C? A) H2(g) B) F2(g) C) O2(g) D) N2(g) E) Cl2(g)
E
36) Identify the indicator that can be used at the highest pH. A) alizarin B) thymol blue C) crystal violet D) phenolphthalein E) alizarin yellow R
E
37) Which of the following acids is the STRONGEST? The acid is followed by its Ka value. A) HF, 3.5 × 10-4 B) HCN, 4.9 × 10-10 C) HNO2, 4.6 × 10-4 D) H COOH, 1.8 × 10-4 E) HClO2, 1.1 × 10-2
E
38) What can change the direction of a reversible reaction? A) change in temperature B) change in pressure C) change in volume D) none of the above E) all of the above
E
4) Which of the following processes have a ΔS < 0? A) water freezes B) methyl alcohol condenses C) propanol (g, at 555 K) → propanol (g, at 400 K) D) carbon dioxide(g) → carbon dioxide(s) E) All of the above processes have a ΔS < 0.
E
40) Give the name of the reaction that does not achieve the theoretical limits with respect to free energy in thermodynamics. A) reversible reaction B) forward reaction C) reverse reaction D) equilibrium reaction E) irreversible reaction
E
45) A 100.0 mL sample of 0.10 M NH3 is titrated with 0.10 M HNO3. Determine the pH of the solution after the addition of 100.0 mL of HNO3. The Kb of NH3 is 1.8 × 10-5. A) 6.58 B) 10.56 C) 8.72 D) 3.44 E) 5.28
E