Chemistry 102 Exam 3

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A____ M solution of Ba(OH)2 has a pH of 12.7 .

2.5 ×10 ^-2

Find the percent ionization of a 0.337 M HF solution. The Ka for HF is 3.5×10 ^-4

3.2%

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

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

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

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

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

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

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

Strong Acids

H-Cl, H-Br, H-I, H2SO4, HNO3, HClO4

Strong Bases

NaOH, KOH, LiOH, Ca(OH)2

Amphoteric

Substances that can act as acids or bases

a.) Use henderson-hasslelbalch to calculate pH of a solution that is 0.135 M HClO and 0.155 M KClO. b.) add 0.35 mol HCl (assume this solution is 1 L)

a.) pH=7.6 b.) pH=7.4

36) Calculate the molarity of hydroxide ion in an aqueous solution that has a pOH of 5.00. A) 1.0 × 10-5 B) 9.00 C) 1.0 × 10-9 D) 5.0 × E) 9.0 × 10-14

A

produces protons in aqueous solution

Arrhenius acid

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

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

14) Which of the following is a STRONG acid? A) C6H5CO2H B) HCN C) HClO4 D) NH4+ E) H2O

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

18) Calculate the pOH of a solution that contains 3.9 x 10-5 M H3O⁺ at 25°C. A) 5.41 B) 4.41 C) 9.59 D) 8.59 E) 0.59

C

20) Calculate the pH of a solution that contains 2.4 × 10-5 M H3O⁺ at 25°C. A) 2.40 B) 9.38 C) 4.62 D) 8.38 E) 5.62

C

38) Determine the pH in a 0.235 M NaOH solution. A) 13.76 B) 0.24 C) 13.37 D) 0.63 E) 12

C

39) What is the hydronium ion concentration of a 0.500 M acetic acid solution with Ka = 1.8 × 10-5? The equation for the dissociation of acetic acid is: CH3CO2H(aq) + H2O(l) ⇌ H3O+(aq) + CH3CO2-(aq). A) 3.0 × 10-2 M B) 4.2 × 10-2 M C) 3.0 × 10-3 M D) 4.2 × 10-3 M

C

4) Identify the base that is in baking soda. A) RbOH B) NaOH C) NaHCO3 D) Li2CO3 E) NH3

C

41) Determine the [OH-] concentration of a 0.741 M KOH solution at 25°C. A) 1.34 x 10-13 M B) 1.34 x 10-14 M C) 0.741 M D) 7.41 M E) none of the above

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

45) Determine the pOH of a 0.227 M C5H5N solution at 25°C. The Kb of C5H5N is 1.7 × 10-9. A) 4.59 B) 9.41 C) 4.71 D) 10.14 E) 9.29

C

55) What is the pH of a 0.30 M pyridine solution that has Kb = 1.9 × 10-9? The equation for the dissociation of pyridine is C5H5N(aq) + H2O(l) ⇌ C5H5NH+(aq) + OH-(aq). A) 4.62 B) 8.72 C) 9.38 D) 10.38

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

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

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

40) What is the hydronium ion concentration of a 0.150 M hypochlorous acid solution with Ka = 3.5 × 10-8? The equation for the dissociation of hypochlorous acid is: HOCl(aq) + H2O(l) ⇌ H3O+(aq) + OCl-(aq). A) 1.9 × 10-4 M B) 7.2 × 10-4 M C) 2.8 × 10-5 M D) 7.2 × 10-5 M

D

42) Determine the pH of a 0.188 M NH3 solution at 25°C. The Kb of NH3 is 1.76 × 10-5. A) 5.480 B) 2.740 C) 8.520 D) 11.260 E) 12.656

D

43) Calculate the pH of a 1.60 M KBrO solution. Ka for hypobromous acid, HBrO, is 2.0 × 10-9. A) 2.55 B) 4.25 C) 9.75 D) 11.45

D

A mixture of 0.1 M NaOH and 0.125M NH3, would have a pH of what? The Kb of NH3 is 1.76×10^-5

13.0

What is the pH of a mixture of 0.150 M HCHO2 and 0.125 M HClO? The Ka of HCHO2 is 1.8×10^-4 and 2.9×10^-8 for HClO.

2.28

Determine the pH of a 0.62 M NH4NO3 solution at 25°C.

4.73

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

Br∅nsted- Lowery acids and bases

*Acid: proton donor *Base: proton accepter *Illustrated reversible reaction

Arrhenius acids and base

*Acids: A substance that produces H+ ions in aqueous solution. -Ionizes in water *Base: A substance that produces OH- ions in aqueous solution -dissociates in water *Acid and base combine to make water (neutralizing each other)

Lewis acids and bases

*Base: has a lone pair of electrons of which it is willing to donate to the acid

Autoionization

*When something acts as an acid and a base with itself. -Water is a specific example

Identify the strongest acid: A. HBrO B. HClO C. HClO2 D. HClO3 E. HClO4

E. HClO4

Find the pH of a 1.25×10^-3 M NaOH solution

pH=11.10

What is the pH of a solution containing 0.1 M of Ca(OH)2?

pH=13.30

equivalence point of a weak base/strong acid titration

ph<7

equivalence point of a strong acid/strong base titration

ph=7

True or False: An acid/base and its conjugate must be present in order to use the henderson-hasslelbalch equation.

True

A buffer contains significant amounts of acetic acid and sodium acetate. Write an equation showing how the buffer neutralizes added acid or base.

a.) HCl +NaC2H3O2↔HC2H3O2 +NaCl b.) HC2H3O2 +NaOH↔H2O +NaC2H3O2

A buffer contains a significant amount of ammonia and ammonium chloride.Write an equation showing how the buffer neutralizes added acid or base.

a.) NaOH + NH4Cl↔ NH3 +H2O+NaCl b.) HCl+NH3↔NH4 + Cl

What effect will the salt C2H5NH3NO3 have on the acidity/basicity of a solution?

acidic

23) Calculate the hydronium ion concentration in an aqueous solution that contains 2.50 × 10-6 M in hydroxide ion. A) 4.00 × 10-7 M B) 4.00 × 10-8 M C) 4.00 × 10-9 M D) 5.00 × 10-9 M

C

24) Calculate the hydroxide ion concentration in an aqueous solution that contains 3.50 × 10-4 M in hydronium ion. A) 2.86 × 10-3 M B) 2.86 × 10-10 M C) 2.86 × 10-11 M D) 3.50 × 10-11 M

C

24) Determine the pH of a 0.023 M HNO3 solution. A) 12.36 B) 3.68 C) 1.64 D) 2.30 E) 2.49

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) 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

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

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

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

48) Determine the Kb for CN⁻ at 25°C. The Ka for HCN is 4.9 × 10-10. A) 4.9 × 10-14 B) 2.3 × 10-9 C) 1.4 × 10-5 D) 2.0 × 10-5 E) 3.7 × 10-7

D

50) Determine the pH of a 0.62 M NH4NO3 solution at 25°C. The Kb for NH3 is 1.76 × 10-5. A) 2.48 B) 9.27 C) 11.52 D) 4.73 E) 9.45

D

50) Determine the pOH of a 0.348 M Ba(OH)2 solution at 25°C. A) 13.08 B) 13.54 C) 13.84 D) 0.157 E) 0.458

D

53) What is the pH of a 0.040 M Ba(OH)2 solution? A) 1.10 B) 1.40 C) 12.60 D) 12.90

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

56) Identify the strongest acid. A) H2O B) H2S C) H2Se D) H2Te E) not enough information is available

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

49) Determine the Ka for CH3NH3⁺ at 25°C. The Kb for CH3NH2 is 4.4 × 10-4. A) 3.1 × 10-10 B) 6.8 × 10-11 C) 5.6 × 10-10 D) 2.3 × 10-3 E) 2.3 × 10-11

E

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

6) Identify the weak diprotic acid. A) CH3COOH B) HCOOH C) H3PO4 D) H2SO4 E) H2CO3

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

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

How do you determine the pH of a mixture between: A. Two strong acids? B. A strong acid and a weak acid? C. Two weak acids?

A. Add the concentrations B. only consider the strong C. look at the Ka and use the higher value

13) Identify the triprotic acid. A) HNO3 B) H3PO4 C) H2CO3 D) HFO4 E) H2SO4

B

17) What is the Kw of pure water at 50.0°C, if the pH is 6.630? A) 2.34 × 10-7 B) 5.50 × 10-14 C) 2.13 × 10-14 D) 1.00 × 10-14

B

19) Calculate the pH of a solution that contains 3.9 x 10-5 M H3O⁺ at 25°C. A) 5.41 B) 4.41 C) 9.59 D) 8.59 E) 0.59

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

21) Calculate the pOH of a solution that contains 2.4 × 10-5 M H3O⁺ at 25°C. A) 2.40 B) 9.38 C) 4.62 D) 8.38 E) 5.62

B

25) A solution with a hydrogen ion concentration of 3.25 × 10-6 M is ________ and has a hydroxide ion concentration of ________. A) acidic, 3.08 × 10-8 M B) acidic, 3.08 × 10-9 M C) basic, 3.08 × 10-8 M D) basic, 3.08 × 10-9 M

B

28) Calculate the pOH of a solution that contains 7.8 x 10-6 M OH⁻ at 25°C. A) 1.28 B) 5.11 C) 12.72 D) 8.89 E) 9.64

B

31) What is the hydronium ion concentration of an acid rain sample that has a pH of 3.45? A) 2.82 × 10-11 M B) 3.55 × 10-4 M C) 3.45 M D) 10.55 M

B

32) What is the hydroxide ion concentration of a lye solution that has a pH of 9.20? A) 6.31 × 10-10 M B) 1.58 × 10-5 M C) 4.80 M D) 9.20 M

B

35) Determine the Ka of an acid whose 0.294 M solution has a pH of 2.80. A) 1.2 × 10-5 B) 8.5 × 10-6 C) 2.7 D) 4.9 × 10-7 E) 5.4 × 10-3

B

43) Determine the pOH of a 0.188 M NH3 solution at 25°C. The Kb of NH3 is 1.76 × 10-5. A) 5.480 B) 2.740 C) 8.520 D) 11.260 E) 12.656

B

47) Determine the pH of a 0.741 M LiOH solution at 25°C. A) 0.130 B) 13.87 C) 0.741 D) 13.26 E) 1.48

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

56) Determine the ammonia concentration of an aqueous solution that has a pH of 11.00. The equation for the dissociation of NH3 (Kb = 1.8 × 10-5) is NH3(aq) + H2O(l) ⇌ NH4+(aq) + OH-(aq). A) 3.0 M B) 0.056 M C) 1.8 × 10-2 M D) 1.0 × 10-3 M

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

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

proton donor

Bronsted-Lowry acid

proton acceptor

Bronsted-Lowry base

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

22) Calculate the pOH in an aqueous solution with a pH of 7.85 at 25°C. A) 4.15 B) 5.15 C) 6.15 D) 7.15 E) 8.15

C

Calculate the hydroxide ion concentration in an aqueous solution with a pH of 9.85 at 25°C.

7.1×10^-5 M

Calculate the pH of a solution that contains 7.8×10^-6 M OH- at 25°C.

8.89

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

10) Which of the following is a Br∅nsted-Lowry acid? A) NH4+ B) CCl4 C) NH2- D) NH3 E) Br2

A

16) What is the pH of pure water at 40.0°C if the Kw at this temperature is 2.92 × 10-14? A) 6.767 B) 0.465 C) 7.000 D) 7.233 E) 8.446

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

2) Identify the acid that is in car batteries. A) H2SO4 B) HNO3 C) H2CO3 D) CH3COOH E) HCl

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) Calculate the hydroxide ion concentration in an aqueous solution with a pH of 9.85 at 25°C. A) 7.1 × 10-5 M B) 4.2 × 10-10 M C) 8.7 × 10-10 M D) 6.5 × 10-5 M E) 1.4 × 10-10 M

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) Calculate the hydronium ion concentration in an aqueous solution with a pOH of 9.85 at 25°C. A) 7.1 × 10-5 M B) 4.2 × 10-10 M C) 8.7 × 10-10 M D) 6.5 × 10-5 M E) 1.4 × 10-10 M

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

26) Determine the pOH of a 0.00598 M HClO4 solution. A) 11.777 B) 6.434 C) 7.566 D) 2.223 E) 3.558

A

29) Calculate the hydroxide ion concentration in an aqueous solution with a pH of 4.33 at 25°C. A) 2.1 × 10-10 M B) 9.7 × 10-10 M C) 4.7 × 10-5 M D) 3.8 × 10-5 M E) 6.3 × 10-6 M

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) Calculate the hydronium ion concentration in an aqueous solution with a pOH of 4.33 at 25°C. A) 2.1 × 10-10 M B) 9.7 × 10-10 M C) 4.7 × 10-5 M D) 3.8 × 10-5 M E) 6.3 × 10-6 M

A

34) An aqueous solution at 25.0°C contains [H+] = 0.099 M. What is the pH of the solution? A) 1.00 B) -1.00 C) 13.0 D) 0.0990 E) 1.00 ×

A

34) Determine the pH of a 0.461 M C6H5CO2H M solution if the Ka of C6H5CO2H is 6.5 x 10-5. A) 2.26 B) 4.52 C) 11.74 D) 9.48 E) 5.48

A

35) The pH of an aqueous solution at 25.0°C is 10.66. What is the molarity of H+ in this solution? A) 2.2 × 10-11 B) 4.6 × 10-4 C) 3.3 D) 1.1 × 10-13 E) 4.6 × 1010

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

4) What is the conjugate base of H2PO4⁻ ? A) HPO42- B) PO43- C) H3PO4 D) H3O+ E) OH⁻

A

40) Determine the [OH⁻] concentration in a 0.169 M Ca(OH)2 solution. A) 0.338 M B) 0.169 M C) 5.92 × 10-14 M D) 2.96 × 10-14 M E) 0.298 M

A

41) The acid-dissociation constant at 25.0°C for hypochlorous acid (HClO) is 3.0 × 10-8. At equilibrium, the molarity of H3O+ in a 0.010 M solution of HClO is ________. A) 1.7 × 10-5 B) 0.010 C) 5.8 × 10-10 D) 4.76 E) 2.00

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

48) Determine the pOH of a 0.741 M LiOH solution at 25°C. A) 0.130 B) 13.87 C) 0.741 D) 13.26 E) 1.48

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

52) A 7.0 × 10-3 M aqueous solution of Ca(OH)2 at 25.0°C has a pH of ________. A) 12.15 B) 1.85 C) 1.4 × 10-2 D) 7.1 × 10-13 E) 11.85

A

52) In a triprotic acid, which Ka has the highest value? A) Ka1 B) Ka2 C) Ka3 D) Kb1 E) Kb2

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

58) Calculate the pH of a 1.60 M CH3NH3Cl solution. Kb for methylamine, CH3NH2, is 3.7 × 10-4. A) 1.61 B) 5.18 C) 8.82 D) 12.39

A

6) Calculate the pH of a solution that is 0.295 M in sodium formate (NaHCO2) and 0.205 M in formic acid (HCO2H). The Ka of formic acid is 1.77 × 10-4. A) 3.910 B) 3.587 C) 13.84 D) 10.10 E) 4.963

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

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) 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) 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

produces hydroxide ions in aqueous solution

Arrhenius base

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<HBrO3< HBrO3 < HBrO2

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

Which of the following is NOT a conjugate acid-base pair? A. NH4+/NH3 B. H2CO3/CO3^2- C. H2SO3/HSO3- D. C2H3O2-/HC2H3O2 E. all of the above

B. H2CO3/CO3^2-

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

27) Calculate the pH for an aqueous solution of acetic acid that contains 2.15 × 10-3 M hydronium ion. A) 4.65 × 10-12 M B) 2.15 × 10-3 M C) 2.67 D) 11.33

C

27) The highest pH for an effective buffer occurs when the base is how many times as concentrated as the acid? A) 8 B) 5 C) 10 D) 25 E) 40

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

30) Calculate the hydronium ion concentration in an aqueous solution with a pH of 4.33 at 25°C. A) 2.1 × 10-10 M B) 9.7 × 10-10 M C) 4.7 × 10-5 M D) 3.8 × 10-5 M E) 6.3 × 10-6 M

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

33) What is the pH of a 0.020 M HClO4 solution? A) 0.020 B) 0.040 C) 1.70 D) 12.30

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

49) Determine the pH of a 0.232 M Mg(OH)2 solution at 25°C. A) 12.73 B) 13.37 C) 13.67 D) 0.333 E) 0.634

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

51) Determine the [OH-] concentration of a 0.123 M Sr(OH)2 solution at 25°C. A) 4.06 x 10-14 M B) 0.123 M C) 0.246 M D) 8.13 x 10-14 M E) 0.0615 M

C

51) Determine the pH of a 0.22 M NaF solution at 25°C. The Ka of HF is 3.5 × 10-5. A) 10.20 B) 5.10 C) 8.90 D) 11.44 E) 2.56

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) In which of the following solutions would solid PbBr2 be expected to be the least soluble at 25°C? A) 0.1 M HBr B) 0.1 M NaBr C) 0.1 M CaBr2 D) 0.1 M K NO3

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

67) Which of the following is a triprotic acid? A) HI B) H2SO4 C) H3PO4 D) CCl4 E) HC2H3O2

C

7) Identify the weak diprotic acid. A) HNO3 B) H3PO4 C) H2SO3 D) HClO4 E) H2SO4

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

The stronger the acid, then which of the following is TRUE? A. The stronger the conjugate base B. The stronger the conjugate acid C. The weaker the conjugate base D. The weaker the conjugate acid E. none of the above

C. The weaker the conjugate base

15) Which of the following is a WEAK acid? A) HClO4 B) H2SO4 C) HBr D) HCN E) HNO3

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

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

25) Determine the pH of a 0.00598 M HClO4 solution. A) 11.777 B) 6.434 C) 7.566 D) 2.223 E) 3.558

D

26) A solution with a hydroxide ion concentration of 4.15 × 10-6 M is ________ and has a hydrogen ion concentration of ________. A) acidic, 2.41 × 10-8 M B) acidic, 2.41 × 10-9 M C) basic, 2.41 × 10-8 M D) basic, 2.41 × 10-9 M

D

27) Calculate the pH of a solution that contains 7.8 x 10-6 M OH⁻ at 25°C. A) 1.28 B) 5.11 C) 12.72 D) 8.89 E) 9.64

D

28) Calculate the pH for an aqueous solution of pyridine that contains 2.15 × 10-4 M hydroxide ion. A) 4.65 × 10-11 B) 2.15 × 10-4 C) 3.67 D) 10.33

D

3) Identify the acid that is in vinegar. A) H2SO4 B) HNO3 C) Na2CO3 D) CH3COOH E) HF

D

30) 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

33) Identify the most common indicator. A) alizarin B) thymol blue C) crystal violet D) phenolphthalein E) thymolphthalein

D

39) Determine the pOH in a 0.235 M NaOH solution. A) 13.76 B) 0.24 C) 13.37 D) 0.63 E) 12

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

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

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

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

Identify the weak diprotic acid: A. HNO3 B. H2SO4 C. H3PO4 D. H2SO3 E. HClO4

D. H2SO3

What is the conjugate acid of HCO3-? A. H3O+ B. H2O C.OH- D.H2CO3 E. CO3^2-

D.H2CO3

15) What is the concentration of hydroxide ions in pure water at 30.0∘C, if Kw at this temperature is 1.47 × 10-14? A) 1.00 × 10-7 M B) 1.30 × 10-7 M C) 1.47 × 10-7 M D) 8.93 × 10-8 M E) 1.21 × 10-7 M

E

20) Calculate the hydronium ion concentration in an aqueous solution with a pH of 9.85 at 25°C. A) 7.1 × 10-5 M B) 4.2 × 10-10 M C) 8.7 × 10-10 M D) 6.5 × 10-5 M E) 1.4 × 10-10 M

E

23) Calculate the hydroxide ion concentration in an aqueous solution with a pOH of 9.85 at 25°C. A) 7.1 × 10-5 M B) 4.2 × 10-10 M C) 8.7 × 10-10 M D) 6.5 × 10-5 M E) 1.4 × 10-10 M

E

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

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) Determine the [H3O⁺] in a 0.265 M HClO solution. The Ka of HClO is 2.9 × 10-8. A) 1.1 × 10-10 M B) 7.7 × 10-9 M C) 1.3 × 10-6 M D) 4.9 × 10-4 M E) 8.8 × 10-5 M

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

44) Determine the pH of a 0.227 M C5H5N solution at 25°C. The Kb of C5H5N is 1.7 × 10-9. A) 4.59 B) 9.41 C) 4.71 D) 10.14 E) 9.29

E

44) Which of the following is a STRONG base? A) I- B) NH3 C) CH3OH D) NO3⁻ E) LiOH

E

46) Determine the [OH⁻] concentration in a 0.235 M NaOH solution. A) 4.25 × 10-14 M B) 0.470 M C) 2.13 × 10-14 M D) 0.118 M E) 0.235 M

E

Which of the following will form a basic solution in water? A. NaC2H3O2 B. LiBrO C. LiCN D. KClO2 E. all of the above

E. all of the above

Which one of the following is a Br∅nsted- Lowery acid? A. (CH3)3NH+ B. HC2H3CO2 C. HF D. HNO2 E. all of the above

E. all of the above

electron pair acceptor

Lewis acid

electron pair donor

Lewis base

half-way to equivalence point of a weak acid/strong base titration

PH=Pka

3/4 of the way to second equivalence point of a diprotic acid/strong base titration

PH=pka2

equivalence point of a weak acid/strong base titration

Ph>7


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