Chem_1B_Ch15_PT

Exam Name___________________________________

ULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

1) Aceti Aceticc acid acid CH CH 3COOH, has an acid dissociation constant of 1.8 ˛ 10-5. What is the conjugate base of acetic acid and what is its base dissociation constant? A) CH3CO 2 - , 5.6 ˛ 10-10 B) CH3 C(OH)2+ , 5.6 ˛ 10-10 C) CH3COOH, 5.6 ˛ 10-10

D) CH3 C(OH)2+ , 5.6 ˛ 104

2) What is the the selenide selenide ion concentra concentration tion [Se [Se2-] for a 0.200 M H 2 Se solution that has the stepwise dissociation constants of K a1 a2 = 1.0 ˛ 10-11? a1 = 1.3 ˛ 10-4 and K a2 A) 1.0 ˛ 10-11 M

1)

B) 1.3 ˛ 10-4 M

C) 2.6 ˛ 10-5 M

2)

D) 5.1 ˛ 10-3 M

In the following reaction the unshaded spheres represent H atoms.

3) Identify Identify the BrMnsted-Lowry acid/base conjugate pairs. A) (1 ( 1)/(4) and (2)/(3)

B) (1 ( 1)/(3) and (2)/(4)

3) C) (1 ( 1)/(2) and (3)/(4)

4) Identify Identify the BrMnsted-Lowry bases. A) (2) and (3)

4)

B) (2) and (4)

C) (1) and (3)

D) (1) and (4)

5) A solution with with a hydrogen hydrogen ion concentrati concentration on of 3.25˛ 10-5 M is ________ and has a hydroxide ion concentration of ________. A) acidic acidic,, 3.08 ˛ 10-10 M B) acidic, 3.08 ˛ 10-9 M C) basic, basic, 3.08 3.08 ˛ 10-9 M

D) basic, 3.08 ˛ 10-10 M

6) Whic Which h Br BrMnsted-Lowry acid has the strongest conjugate base? A) HBr

B) HF

C) HI

6) D) HClO4

7) Calculate Calculate the pH of a 0.100 0.100 M CH CH3 NH3 Cl solution. K b for methylamine, CH3 NH2 , is 3.7 ˛ 10-4. A) 5.78

5)

B) 8.22

C) 11.78

1

D) 2.22

7)

8) Methy Methyla lami mine ne CH3 NH2 , has a base dissociation constant of 3.7 ˛ 10-4. What is the conjugate acid of methylamine and what is its acid dissociation constant? A) CH3NH 3 + , 2.7 ˛ 10-11 B) CH3 NH2 - , 2.7 ˛ 10-11 C) CH3NH 3 + , 3.7 ˛ 10-4

D) CH3 NH3 + , 2.7 ˛ 103

9) Which one of the following following salts, when dissolved dissolved in water, produces produces the solution with thelowest pH? A) NaI

B) AlI3

C) KI

A) HCl, HCl, H3 O+

B) HCl, HCl, H2O

C) HCl, HCl, H2 O, H 3O+

D) HCl, HCl, Cl Cl -

10)

11) 11) Ammon Ammonia ia NH3 , has a base dissociation constant of 1.8 ˛ 10-5. What is the conjugate acid of ammonia and what is its acid dissociation constant? A) NH 2 - , 5.6 ˛ 10-10 B) NH 4+ , 1.8 ˛ 10-5 C) NH 4 + , 1.9 ˛ 109

9)

D) MgI2

10) Indica Indicate te all all the the BrMnsted-Lowry acids in the following chemical reaction HCl(aq) + H2O( aq) Ì H3 O+(aq) + Cl - (aq).

11)

D) NH 4+ , 5.6 ˛ 10-10

12) 12) Anil Anilin ine, e, (C6H5NH 2 , K b = 4.3 ˛ 10-10 at 25e C) is an industrially important amine used in the making of dyes. Determine the pH of an aniline solution made by dissolving 6.90 g of aniline in enough water to make 100 mL of solution. A) 9.50

8)

B) 9.25

C) 4.75

13) What is the the strongest strongest base among among the following? following? A) ClO2 B) ClO ClO4-

12)

D) 10.50 13)

C) ClO ClO3 -

D) ClO ClO-

The following pictures represent equal volumes of aqueous solutions of three acids HA (A = X, Y, or Z); water molecules have been omitted for clarity.

14) Arrange Arrange the acids in order order of increasing increasing value value of K K a .

14)

A) K a (HZ) < K a (HY) < K a (HX)

B) K a (HY) < K a (HZ) < K a (HX)

C) K a (HX) < K a (HZ) < K a (HY)

D) K a (HZ) < K a (HX) < K a (HY)

2

8) Methy Methyla lami mine ne CH3 NH2 , has a base dissociation constant of 3.7 ˛ 10-4. What is the conjugate acid of methylamine and what is its acid dissociation constant? A) CH3NH 3 + , 2.7 ˛ 10-11 B) CH3 NH2 - , 2.7 ˛ 10-11 C) CH3NH 3 + , 3.7 ˛ 10-4

D) CH3 NH3 + , 2.7 ˛ 103

9) Which one of the following following salts, when dissolved dissolved in water, produces produces the solution with thelowest pH? A) NaI

B) AlI3

C) KI

A) HCl, HCl, H3 O+

B) HCl, HCl, H2O

C) HCl, HCl, H2 O, H 3O+

D) HCl, HCl, Cl Cl -

10)

11) 11) Ammon Ammonia ia NH3 , has a base dissociation constant of 1.8 ˛ 10-5. What is the conjugate acid of ammonia and what is its acid dissociation constant? A) NH 2 - , 5.6 ˛ 10-10 B) NH 4+ , 1.8 ˛ 10-5 C) NH 4 + , 1.9 ˛ 109

9)

D) MgI2

10) Indica Indicate te all all the the BrMnsted-Lowry acids in the following chemical reaction HCl(aq) + H2O( aq) Ì H3 O+(aq) + Cl - (aq).

11)

D) NH 4+ , 5.6 ˛ 10-10

12) 12) Anil Anilin ine, e, (C6H5NH 2 , K b = 4.3 ˛ 10-10 at 25e C) is an industrially important amine used in the making of dyes. Determine the pH of an aniline solution made by dissolving 6.90 g of aniline in enough water to make 100 mL of solution. A) 9.50

8)

B) 9.25

C) 4.75

13) What is the the strongest strongest base among among the following? following? A) ClO2 B) ClO ClO4-

12)

D) 10.50 13)

C) ClO ClO3 -

D) ClO ClO-


14) Arrange Arrange the acids in order order of increasing increasing value value of K K a .

14)

A) K a (HZ) < K a (HY) < K a (HX)

B) K a (HY) < K a (HZ) < K a (HX)

C) K a (HX) < K a (HZ) < K a (HY)

D) K a (HZ) < K a (HX) < K a (HY)

2

15) Determine Determine the acid dissociation dissociation constant constant for a 0.10 M acetic acid solution solution that has a pH of 2.87. Acetic acid is a weak monoprotic acid and the equilibrium equation of interest is CH3 COOH(aq) + H2 O( l ) Ì H3 O+(aq) + CH3 CO 2 -(aq). A) 1.3 ˛ 10-2

B) 1.8 1.8 ˛ 10-6

C) 1.3 1.3 ˛ 10-3

D) 1.8 1.8 ˛ 10-5

16) A solution with with a hydroxide hydroxide ion concentr concentration ation of 4.15 4.15 ˛ 10-4 M is ________ and has a hydrogen ion concentration of ________. A) acidic acidic,, 2.41 ˛ 10-10 M B) basic, 2.41 ˛ 10-11 M C) acidic acidic,, 2.41 ˛ 10-11 M

15)

16)

D) basic, 2.41 ˛ 10-10 M

The following pictures represent solutions of three salts MA; water molecules have been omitted for clarity. Dotted spheres represent A y- ions; gray spheres represent Mx+ ions; black spheres represent oxygen atoms; and unshaded spheres represent hydrogen atoms.

17) Which picture represents represents a neutral neutral salt? salt?

17)

A) (1)

B) (2)

C) (3)

D) none of the above

18) What is is the pH of a 0.020 0.020 M Ba(OH)2 solution? A) 1.40

18)

B) 12.60

C) 12.30

D) 1.70

19) When dissolved dissolved in water, which of the following following compounds compounds is an Arrhenius acid? acid? A) NaF

B) HCN

C) NaOH

D) CH 3 CH2 OH

20) From the following following chemical chemical reactions reactions determine determine the relative relative BrMnsted-Lowry base strengths (strongest to weakest). HNO3 (aq) + H2 O(l) ¬ H 3 O+(aq) + NO 3 - (aq) HF(aq) + H2O( l) Ì H3O+(aq) + F- (aq) A) F- > H2 O > NO 3-

B) F- > NO3 - > H2O

C) HNO3 > H3O+ > HF

D) NO3 - > H2 O > F-

21) What is the hydronium ion concentration of an acid rain sample that has a pH of 3.35? 35? A) 4.47 4.47 ˛ 10-4 M B) 3.35 M C) 2.24 ˛ 10-11 M D) 10.65 M

3

19)

20)

21)

22) Of the elements indicated on the periodic table shown above, which forms the weakest binary acid, H2X or HX, where X = A, B, C, or D? A) A

B) B

C) C

D) D

23) The percent dissociation of acetic acid changes as the concentration of the acid decreases. A 100-fold decrease in acetic acid concentration results in a ________ fold ________ in the percent dissociation. A) 100, decrease

B) 100, increase

22)

C) 10, increase

23)

D) 10, decrease

24) Which one of the following can behave either as a BrMnsted-Lowry acid or a BrMnsted-Lowry base in an aqueous solution reaction? A) H3 PO4 B) HI C) HSO3 D) NH 3

24)

25) What is the pH of a 2.4 M pyridine solution that has K b = 1.9 ˛ 10-9? The equation for the dissociation of pyridine is C5 H5N(aq) + H2 O( l ) Ì C5H5NH +(aq) + OH-(aq).

25)

A) 8.72

B) 9.83

C) 4.17

D) 10.83

26) What is the conjugate base of the BrMnsted-Lowry acid HPO4 2-? A) HPO4 2-

26)

C) PO43-

B) H3PO4

D) H2 PO4 -

27) What is the approximate pH of a solution X that gives the following responses with the indicators shown? Indicators

HIn π In-

pH range

Solution X

methyl orange

red-yellow

3.2-4.4

yellow

methyl red

red-yellow

4.8-6.0

yellow

bromthymol blue phenolphthalein A) 4.8 - 6.0

yellow-blue colorless-pink

6.0-7.6 8.2-10.0

B) 6.0 - 7.6

C) 3.2 - 4.4

4

green colorless D) 8.2 - 10.0

27)

28) What is the hydronium ion concentration of a 0.100 M acetic acid solution with aK a = 1.8 ˛ 10-5? The equation for the dissociation of acetic acid is: CH3 CO 2H(aq) + H2 O( l) Ì H3 O+(aq) + CH3 CO 2 - (aq). A) 1.3 ˛ 10-3 M

B) 4.2 ˛ 10-3 M

C) 4.2 ˛ 10-2 M

28)

D) 1.3 ˛ 10-2 M

29) Vinegar is a 5.0% solution by weight of acetic acid (CH3 COOH) in water. Given that the pH for acetic acid is 2.41, the K a = 1.8 ˛ 10-5 and assuming the density of vinegar to be 1.00 g/cm3 , what

29)

is the percent dissociation of acetic acid in vinegar? A) 4.0%

B) 5.0%

C) 0.47%

D) 1.5%

30) Identify the conjugate acid/base pairs present in an aqueous solution of hydrogen sulfate ion HSO4 -. A) H2 SO4 /HSO4 - and H2 O/OH-

B) HSO4 - /H2 O and H 3O+/SO4 2-

C) HSO4- /H2 O and H2 SO4 /OH-

D) HSO4 - /SO4 2- and H3O+/H2O

30)


31) Which picture represents a basic salt?

31)

A) (1)

B) (2)

C) (3)


32) What is the pH of a 0.10 M H2Se solution that has the stepwise dissociation constants K a1 = 1.3 ˛ 10-4 and K a2 = 1.0 ˛ 10-11 ? A) 2.44

B) 5.50

C) 4.89

32)

D) 3.89

33) What is the hydroxide ion concentration of a lye solution that has a pH of 11.20? A) 1.58 ˛ 10-3 M B) 2.80 M C) 6.31 ˛ 10-12 M D) 11.20 M

33)

34) Calculate the hydronium ion concentration in an aqueous solution that contains 2.50˛ 10-3 M in hydroxide ion? A) 4.00 ˛ 10-12 M B) 5.00 ˛ 10-12 M C) 4.00 ˛ 10-11 M D) 4.00 ˛ 10-10 M

34)

5

35) Calculate the concentration of bicarbonate ion, HCO3 - , in a 0.040 M H 2 CO 3 solution that has the stepwise dissociation constants K a1 = 4.3 ˛ 10-7 and K a2 = 5.6 ˛ 10-11. A) 4.3 ˛ 10-7 M

B) 1.7 ˛ 10-8 M

C) 5.6 ˛ 10-11 M

D) 1.3 ˛ 10-4 M

36) What is the pH of a solution prepared by mixing 100.00 mL of 0.20 M HCl with 50.00 mL of 0.10 M HCl? Assume that the volumes are additive. A) 0.15

B) 1.70

C) 0.78

37) Which one of the following species acts as an acid in water? A) NaH B) NH 4 + C) C6 H6

B) B

C) C

37) D) CH3 NH 2

C) CN-

B) H2O

39) D) Fe3+

40) A solution with a hydroxide ion concentration of 4.15 ˛ 10-4 M is ________ and has a hydrogen ion concentration of ________. A) basic, 2.41 ˛ 10-10 M B) acidic, 2.41 ˛ 10-11 M C) acidic, 2.41 ˛ 10-10 M

40)

D) basic, 2.41 ˛ 10-11 M

41) Determine the acid dissociation constant for a 0.010 M nitrous acid solution that has a pH of 2.70. Nitrous acid is a weak monoprotic acid and the equilibrium equation of interest is HNO2 (aq) + H2 O( l) Ì H3 O+(aq) + NO 2- (aq). A) 4.0 ˛ 10-4

38)

D) D

39) Identify the Lewis acid that acts as a reactant in the following reaction Fe(H2 O) 6 3+(aq) + 6 CN- (aq) ¬ Fe(CN)6 3-(aq) + 6 H2 O( l). A) Fe(H2 O)6 3+

36)

D) 0.52

38) Of the elements indicated on the periodic table shown above, which forms the weakest oxoacid acid with the formula H2 XO3 or HXO3 , where X = A, B, C, or D? A) A

35)

B) 5.0 ˛ 10-4

C) 8.0 ˛ 10-3

6

D) 2.0 ˛ 10-3

41)

42) Which of the above pictures represents a solution of a weak diprotic acid H2A for which K a1 >> K a2? (Water molecules have been omitted for clarity.) A) picture (a)

B) picture (b)

C) picture (c)

D) picture (d)

43) What is the strongest acid among the following? A) H2 O

42)

43)

B) HF

C) H2 S

7

D) HCl

44) Which of the above pictures represents a solution of a diprotic acid H2 A for which K a1 = « and K a2 is exceptionally small. (Water molecules have been omitted for clarity.) A) picture (a)

B) picture (b)

C) picture (c)

D) picture (d)

45) What is the hydroxide ion concentration and the pH for a hydrochloric acid solution that has a hydronium ion concentration of 1.50 ˛ 10-4 M? A) 6.67 ˛ 10-10 M, 9.18 B) 6.67 ˛ 10-11 M, 3.82 C) 6.67 ˛ 10-10 M, 4.82

B) 11.60

C) 11.30

47)

A) accept a hydroxide ion.

B) donate a proton.

C) accept a proton.

D) donate a hydroxide ion.

48) Calculate the pH of a 0.200 M NaCH3 CO 2 solution. K a for acetic acid, CH3 CO 2 H, is 1.8 ˛ 10-5. B) 11.28

C) 2.72

8

46)

D) 2.70

47) A BrMnsted-Lowry acid is best defined as a substance that can

A) 4.98

45)

D) 6.67 ˛ 10-11 M, 10.18

46) What is the pH of a solution prepared by diluting 25.00 mL of 0.020 M Ba(OH)2 with enough water to produce a total volume of 250.00 mL? A) 2.40

44)

D) 9.02

48)


49) Arrange the acids in order of increasing value of percent dissociation. A) HZ < HX < HY

B) HY < HZ < HX

C) HX < HZ < HY

49) D) HZ < HY < HX

50) What is the hydronium ion concentration of an acid rain sample that has a pH of 3.15? A) 3.15 M B) 7.08 ˛ 10-4 M C) 1.41 ˛ 10-11 M D) 10.85 M

50)

51) What is the pH of a solution made by mixing 100.0 mL of 0.10 M HNO3 , 50.0 mL of 0.20 M HCl, and 100.0 mL of water? Assume that the volumes are additive.

51)

A) 1.10

B) 0.30

C) 1.00

D) 0.82

52) An acidic solution at 25e C will have a hydronium ion concentration ________ and a pH value ________. A) [H3 O+] > 1 ˛ 10-7 M, pH > 7.00 B) [H3 O+] > 1 ˛ 10-7 M, pH < 7.00 C) [H3 O+] < 1 ˛ 10-7 M, pH < 7.00

D) [H3 O+] < 1 ˛ 10-7 M, pH > 7.00

53) Of the elements indicated on the periodic table shown above, which forms the strongest oxoacid acid with the formula H2 XO3 or HXO3 , where X = A, B, C, or D? A) A

52)

B) B

C) C

9

D) D

53)

The following pictures represent aqueous solutions of three acids HA (A = X, Y, or Z); water molecules have been omitted fo clarity.

54) Which acid has the smallest value of K a ?

54)

A) HZ

B) HY

C) HX

D) All have the same K a value.

55) From the following chemical reactions determine the relative BrMnsted-Lowry acid strengths (strongest to weakest). HClO4 (sol) + CH3 COOH(l) ¬ CH3 C2 (OH)2+(sol) + ClO4- (aq) H2SO4(sol) + CH3 COOH(l) Ì CH3 C(OH)2 +(sol) + HSO4 -(sol) A) HClO4 > H2 SO4 > CH3 C(OH)2 +

B) HClO4 > H2SO4 > CH3 COOH

C) HClO4 > CH3 COOH > H 2SO4

D) HClO4 > CH3 C(OH)2 + > H2 SO4

56) What is the strongest acid among the following? A) H2 SO4

56)

B) H2SO3

C) H2 SeO4

D) H2 SeO3

57) Calculate the pH of a 0.20 M H2 SO3 solution that has the stepwise dissociation constants K a1 = 1.5 10-2 and K a2 = 6.3 ˛ 10-8. A) 2.52

55)

B) 1.82

C) 1.26

10

D) 1.32

57)

The following pictures represent aqueous solutions of binary acids of the type HA where the water molecules have bee omitted for clarity.

58) Arrange the acids in order of increasing acid strength. A) D < C < B < A

B) D < A < C < B

C) D < C < A < B

58) D) D < B < A < C

59) What are the BrMnsted-Lowry bases in the following chemical reaction C5 H5N(aq) + H 2 O(l) Ì C5 H5 NH+(aq) + OH-(aq)? A) C5 H5 N, H2 O B) C5 H5N, OHC) C5 H5 N, C 5 H5NH +

59)

D) C5 H5N, H2O, OH-

60) Calculate the pH of a 0.020 M carbonic acid solution, H2 CO 3(aq), that has the stepwise dissociation constants K a1 = 4.3 ˛ 10-7 and K a2 = 5.6 ˛ 10-11 . A) 10.25

B) 4.03

C) 1.70

D) 6.37

61) What is the pH of a solution prepared by mixing 100.00 mL of 0.020 M Ca(OH)2 with 50.00 mL of 0. 100 M NaOH? Assume that the volumes are additive. A) 12.78

B) 13.25

C) 12.95

B) 3.2 ˛ 10-3 M

C) 5.7 ˛ 10-3 M

B) 1.9 ˛ 10-4 M

C) 5.9 ˛ 10-4 M

B) 10.38

C) 8.72

11

63)

D) 1.9 ˛ 10-5 M

64) What is the pH of a 0.30 M pyridine solution that has a K b = 1.9 ˛ 10-9 ? The equation for the dissociation of pyridine is C5 H5N(aq) + H2 O( l ) Ì C5H5NH +(aq) + OH-(aq)? A) 4.62

62)

D) 0.55 M

63) What is the hydronium ion concentration of a 0.100 M hypochlorous acid solution with K a = 3.5 ˛ 10-8? The equation for the dissociation of hypochlorous acid is: HOCl( aq) + H2O( l) Ì H3 O+(aq) + OCl-(aq). A) 5.9 ˛ 10-5 M

61)

D) 12.67

62) Determine the ammonia concentration of an aqueous solution that has a pH of 11.50. The equatio for the dissociation of NH3 ( K b = 1.8 ˛ 10-5) is NH 3(aq) + H2O( l) Ì NH4 +(aq) + OH- (aq) A) 2.5 M

60)

D) 9.38

64)

65) Arrange the following 0.10 M aqueous solutions in order of increasing pH NaOH, HBr, NaCH 3 CO 2 , KBr, NH4 Br.

65)

A) NaOH, NaCH3 CO 2 , KBr, NH4 Br, HBr

B) HBr, NH4Br, KBr, NaCH3 CO 2 , NaOH

C) NaOH, NaCH3 CO 2 , NH4 Br, KBr, HBr

D) HBr, KBr, NH4 Br, NaCH3 CO 2 , NaOH

66) The compound BF3 can be described as a(n) ________. A) Lewis base

B) Arrhenius acid

C) Lewis acid

D) BrMnsted-Lowry acid

66)

67) Which one of the following salts, when dissolved in water, produces the solution with thehighest pH? A) NaHSO4

B) MgO

C) LiClO4

68) Which one of the following is expected to be the strongest Lewis acid? A) Fe+ B) Fe3+ C) Fe2+

D) CH3 NH 3I 68) D) Fe

69) For Cu2+ and CO2 , which will behave as a Lewis acid toward OH- in water? A) only CO2

B) only Cu2+

C) Cu2+ and CO2

D) neither Cu2+ nor CO2

70) CO 2 reacts with H2O to form HCO3- and H+. Which picture below correctly represents the curved arrow notation for the initial Lewis acid-Lewis base interaction in this reaction; what is the Lewis acid and the Lewis base?

A) Picture (2) is correct; CO2 is the Lewis acid and H2O is the Lewis base. B) Picture (1) is correct; CO2 is the Lewis acid and H2O is the Lewis base. C) Picture (1) is correct; H2 O is the Lewis acid and CO2 is the Lewis base. D) Picture (2) is correct; H2 O is the Lewis acid and CO2 is the Lewis base.

12

67)

69)

70)


71) Arrange the three acids in order of increasing acid strength. A) HY < HZ < HX

B) HZ < HY < HX

C) HZ < HX < HY

71) D) HX < HZ < HY

72) Potassium hydrogen phthalate (molar mass = 204.2 g/mol)is one of the most commonly used acids for standardizing solutions containing bases. KHP is a monoprotic weak acid with K a = 3.91 ˛ 10-6. Calculate the pH of the solution that results when 0.80 g of KHP is dissolved in enough water to produce 25.0 mL of solution. A) 5.41

B) 1.95

C) 4.60

D) 3.11

73) Determine the ammonia concentration of an aqueous solution that has a pH of 11.00. The equation for the dissociation of NH3 ( K b = 1.8 ˛ 10-5) is NH 3(aq) + H2 O( l) Ì NH4 +(aq) + OH- (aq). A) 1.8 ˛ 10-2 M

C) 1.0 ˛ 10-3 M

B) 0.055 M

B) CH3 NH3 I

C) LiClO4

B) 2.60

C) 1.00

13

74)

D) NaHSO4

75) What is the pH of a solution prepared by diluting 50.00 mL of 0.10 M HCl with enough water to produce a total volume of 100.00 mL? A) 2.00

73)

D) 3.0 M

74) Which one of the following salts, when dissolved in water, produces the solution with thehighest pH? A) MgO

72)

D) 1.30

75)

76) From the following chemical reactions determine the relative BrMnsted-Lowry base strengths (strongest to weakest). 2 NaH(s) + H2 O( l) ¬ 2 NaOH + H 2 ( g) NH 3(aq) + H2 O( l) Ì NH4 +(aq) + OH- (aq) A) OH- > NH3 > H-

B) OH- > H- > NH3

C) H- > OH- > NH3

D) H- > NH3 > OH-

76)


77) Which acid solution has the lowest pH?

77)

A) HX

B) HZ

C) HY

D) All have the same pH.


78) Identify the BrMnsted-Lowry acids. A) (2) and (3)

78)

B) (1) and (4)

C) (1) and (3)

14

D) (2) and (4)

79) What is the strongest acid among the following? A) Cl3 CCOOH

79)

B) CH3 COOH

C) Cl2 CHCOOH

D) ClCH2 COOH

80) Which one of the following salts, when dissolved in water, produces the solution with a pHclosest to 7.00? A) NaHSO4

B) NH4 Cl

C) RbI

D) BaO

81) What is the hydronium ion concentration of a 0.200 M acetic acid solution with K a = 1.8 ˛ 10-5? The equation for the dissociation of acetic acid is: CH3 CO 2H(aq) + H2 O( l) Ì H3 O+(aq) + CH3 CO 2 - (aq). A) 4.2 ˛ 10-2 M

B) 4.2 ˛ 10-3 M

C) 1.90 ˛ 10-3 M

83) Benzoic acid (C6 H5COOH = HBz) solutions are sometimes used in experiments to determine the molarity of basic solution of unknown concentration. What is the pH of a 0.100 M solution of benzoic acid if K a = 6.5 ˛ 10-5 and the equilibrium equation of interest is HBz(aq) + H2O( l) Ì H3O+(aq) + Bz- (aq). B) 5.19

C) 1.00

B) 2.22

C) 1.82

85) Which one of the following is least able to behave as a Lewis base? A) CH3NH 2 B) (CH 3 )3NH + C) (CH 3 )3 N

C) C

15

84)

D) 1.15 85) D) (CH 3 )2 NH

86) Of the elements indicated on the periodic table shown above, which forms the strongest binary acid, H2 X or HX, where X = A, B, C, or D? B) B

83)

D) 4.19

84) Calculate the pH of a 0.40 M H2 SO3 , solution that has the stepwise dissociation constants K a1 = 1.5 ˛ 10-2 and K a2 = 6.3 ˛ 10-8.

A) A

82)

D) 2.51 ˛ 10-3 M, 11.40 M

C) 2.60 M, 11.40 M

A) 1.11

81)

D) 1.90 ˛ 10-2 M

82) At 25 e C, the pH of a vinegar solution is 2.60. What are the values of [H3 O+] and [OH-] in the solution? A) 3.99 ˛ 10-12 M, 2.51 ˛ 10-3 M B) 2.51 ˛ 10-3 M, 3.99 ˛ 10-12 M

A) 2.59

80)

D) D

86)

87) Calculate the pH of a 0.020 M carbonic acid solution, H2 CO 3(aq), that has the stepwise dissociation constants K a1 = 4.3 ˛ 10-7 and K a2 = 5.6 ˛ 10-11 . A) 6.37

B) 1.70

C) 4.03

87)

D) 10.25

The following pictures represent aqueous solutions of binary acids of the type HA where the water molecules have bee omitted for clarity.

88) Determine the strongest acid of the set. A) A

88)

B) B

C) C

D) D

89) From the following chemical reactions determine the relative BrMnsted-Lowry acid strengths (strongest to weakest). HCl(aq) + H2O( l) ¬ H3 O+(aq) + Cl -(aq) HCN(aq) + H2 O( l) Ì H3 O+(aq) + CN- (aq) A) HCl > H3 O+ > HCN

B) HCl > HCN > H3O+

C) H3 O+ > HCl > HCN

D) HCN > H 3 O+ > HCl

90) When dissolved in water, which compound is generally considered to be an Arrhenius acid? A) K CN

B) NaOH

C) CH3 OH

B) KBr

C) KI

92) Dihydrogen phosphate H2PO4 - , has an acid dissociation constant of 6.2 conjugate base of H2 PO4 - and what is its base dissociation constant?

˛

10-7. What is the

B) H3 PO4 , 1.6 ˛ 10-8

C) HPO4 2- , 1.6 ˛ 10-8

D) H3 PO4 , 1.6 ˛ 106

93) Calculate the pH of a of 0.100 M KBrO solution. K a for hypobromousacid, HBrO, is 2.0 ˛ 10-9. B) 3.15

C) 4.85

16

91)

D) KF

A) HPO4 2- , 1.6 ˛ 106

A) 9.15

90)

D) H2 CO 3

91) Which one of the following salts, when dissolved in water, produces the solution with thehighest pH? A) KCl

89)

D) 10.85

92)

93)

94) What are the BrMnsted-Lowry acids in the following chemical reaction HBr(sol) + CH3COOH(sol) Ì CH3 C(OH)2 +(sol) + Br- (sol)? A) CH3COOH, Br-

B) HBr, CH 3 C(OH)2 +

C) CH3COOH, CH3 C(OH)2+

D) HBr, CH 3 COOH

95) Identify the set of Lewis acids. A) BH3 , BF3 , Cu 2+ , CO2

94)

95) B) CH3 - , NH2- , OH- , F-

C) H3 PO4 , H2PO4 - , HPO4 2- , PO4 3-

D) Cl- , OH- , NH3 , H2 O

96) What is the selenide ion concentration [Se2-] for a 0.100 M H2 Se solution that has the stepwise dissociation constants of K a1 = 1.3 ˛ 10-4 and K a2 = 1.0 ˛ 10-11? A) 1.0 ˛ 10-11 M

B) 1.3 ˛ 10-5 M

C) 1.3 ˛ 10-4 M

96)

D) 3.6 ˛ 10-3 M


97) Which acid, if any, is a strong acid?

97)

A) All are strong acids.

B) HY

C) HX and HZ

D) None are strong acids.

98) What is the pH of a solution prepared by dissolving 0.75 grams of solid CaO (lime) in enough water to make 2.00 L of aqueous Ca(OH)2 (limewater)? CaO(s) + H2 O( l ) ¬ Ca 2+(aq) + 2 OH- (aq) A) 11.83

B) 1.87

C) 2.17

17

D) 12.13

98)

99) Which of the following are weak diprotic acids?

99)

A) carbonic acid - H2CO 3 , oxalic acid - H2 C2 O4 , sulfurous acid - H2 SO3 B) hydrocyanic acid - HCN, sulfuric acid - H2SO4 , phosphoric acid - H3 PO4 C) carbonic acid - H2CO 3 , hydrosulfuric acid - H2 S, acetic acid - CH3 COOH D) formic acid - HCOOH, acetic acid CH3 COOH, benzoic acid C6 H5 COOH In the following reaction the unshaded spheres represent H atoms.

100) Identify the BrMnsted-Lowry acids. A) (1) and (3)

100)

B) (2) and (3)

C) (2) and (4)

D) (1) and (4)

101) What are the conjugate acid-base pairs in the following chemical reaction NH 3(aq) + H2 O( l) Ì NH4 +(aq) + OH- (aq)?

101)

A) NH 3 and NH4+

B) NH 3 , OH- and H2 O, NH4 +

C) NH 3 , NH4 + and H2 O, OH-

D) NH 3 , H2O and NH4 + , OH-

102) Potassium hydrogen phthalate (molar mass = 204.2 g/mol) is one of the most commonly used acids 102) for standardizing solutions containing bases. KHP is a monoprotic weak acid with K a = 3.91 ˛ 10-6. Calculate the pH of the solution that results when 0.40 g of KHP is dissolved in enough water to produce 25.0 mL of solution. A) 3.26

B) 4.30

C) 2.10

D) 5.41

103) What statement is most consistent for an acid with a pH = 3?

103)

A) half a strong as an acid with a pH = 5 B) one hundred times as strong as an acid with a pH = 5 C) twice as strong as an acid with a pH of 5 D) one one-hundredth as strong as an acid with a pH of 5 104) Calculate the hydroxide ion concentration in an aqueous solution that contains 3.50˛ 10-3 M in hydronium ion. A) 2.86 ˛ 10-12 M B) 2.86 ˛ 10-4 M C) 3.50 ˛ 10-12 M D) 2.86 ˛ 10-11 M

104)

105) What is the pH of a 0.10 M H2Se solution that has the stepwise dissociation constants K a1 = 1.3 ˛ 10-4 and K a2 = 1.0 ˛ 10-11 ?

105)

A) 2.44

B) 5.50

C) 4.89

18

D) 3.89

106) What is the pH of a solution prepared by diluting 25.00 mL of 0.10 M HCl with enough water to produce a total volume of 100.00 mL? A) 2.00

B) 1.60

C) 3.20

D) 1.00

107) If the ionization constant of water, K w , at 40e C is 2.92 ˛ 10-14 then what is the hydronium ion concentration for a neutral solution? A) [H3 O+] < 1.71 ˛ 10-7 M B) [H3 O+] > 1.71 ˛ 10-7 M C) [H3 O+] > 1.00 ˛ 10-7 M

106)

107)

D) [H3 O+] = 1.71 ˛ 10-7 M

108) What is the relationship between K a and K b at 25e C for a conjugate acid base pair? A) K b/K a = 1 ˛ 10-14

B) K a /K b = 1 ˛ 10-14

C) K a ˛ K b = 1 ˛ 10-14

D) K a + K b = 1 ˛ 10-14

108)


109) Which acid has the lowest percent dissociation?

109)

A) HZ

B) HY

C) HX

D) All have the same percent dissociation.

110) A solution with a hydrogen ion concentration of 3.25˛ 10-2 M is ________ and has a hydroxide concentration of ________. A) acidic, 3.08 ˛ 10-12 M B) acidic, 3.08 ˛ 10-13 M C) basic, 3.08 ˛ 10-13 M

D) basic, 3.08 ˛ 10-12 M

19

110)


111) Which picture represents an acidic salt?

111)

A) (1)

B) (2)

C) (3)


112) What is the percent dissociation of a benzoic acid solution with pH = 2.59? The acid dissociation constant for this monoprotic acid is 6.5 ˛ 10-5. A) 2.5%

B) 0.50%

C) 3.5%

112)

D) 1.5%

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

113)


114) Arrange the conjugate bases (A- = X- , Y- , or Z- ) in order of increasing base strength. A) Z- < Y- < XB) X- < Z- < YC) Z - < X- < YD) Y - < Z- < X-

114)

115) What is the strongest acid of the following?

115)

A) HOBr

B) HOI

C) HOCl

D) All are equivalent.

116) 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) 10.33 D) 3.67

20

116)

117) An acidic solution at 25e C has A) [H3 O+] = [OH-] > 1 ˛ 10-7 M.

117) B) [H3 O+] < 1 ˛ 10-7 M > [OH- ].

C) [H3 O+] > 1 ˛ 10-7 M > [OH- ].

D) [H3 O+] > [OH- ] > 1 ˛ 10-7 M.

118) Which BrMnsted-Lowry base has the strongest conjugate acid? A) CNB) CH3 CO 2C) NO3 -

118) D) F-

119) Calculate the concentration of bicarbonate ion, HCO3 - , in a 0.010 M H2 CO 3 solution that has the stepwise dissociation constants K a1 = 4.3 ˛ 10-7 and K a2 = 5.6 ˛ 10-11. A) 5.6 ˛ 10-11 M

B) 4.3 ˛ 10-7 M

C) 6.6 ˛ 10-5 M

119)

D) 4.3 ˛ 10-9 M

120) If an equal number of moles of the weak acid CH3 CO 2 H and the strong base KOH are added to water, is the resulting solution acidic, basic, or neutral?

120)

A) neutral B) basic C) acidic D) There is insufficient information provided to answer this question. 121) What is the pH of a solution prepared by dissolving 0.15 gram of solid CaO (lime) in enough water to make 2.00 L of aqueous Ca(OH)2 (limewater)? CaO(s) + H2 O(l) ¬ Ca2+(aq) + 2 OH- (aq) A) 2.57

B) 11.43

C) 11.13

21

D) 2.87

121)

122) The following pictures represent solutions of three salts NaA (A- = X- , Y- , or Z-); water molecules and Na + ions have been omitted for clarity. Arrange the three A- ions in order of decreasing base strength.

A) X- > Y- > Z-

B) X- > Z- > Y-

C) Z - > Y- > XZ-

122)

D) Y - > Z- > X-

123) From the following chemical reactions determine the relative BrMnsted-Lowry acid strengths (strongest to weakest). HClO4 (aq) + H2 O( l) ¬ H 3O+(aq) + ClO4 - (aq) HNO2 (aq) + H2 O(l) Ì H3 O+(aq) + NO 2 - (aq) A) H3 O+ > HNO2 > HClO4

B) HClO4 > H3O+ > HNO2

C) H3 O+ > HClO4 > HNO2

D) HClO4 > HNO2 > H3 O+

123)

124) Calculate the hydroxide ion concentration in an aqueous solution that contains 3.50˛ 10-3 M in hydronium ion? A) 2.86 ˛ 10-4 M B) 2.86 ˛ 10-11 M C) 3.50 ˛ 10-12 M D) 2.86 ˛ 10-12 M

124)

125) What is the strongest acid among the following?

125)

A) HBr

B) HF

C) HCl

22

D) HI


126) Arrange the acids in order of increasing acid strength. A) HZ < HY < HX

B) HZ < HX < HY

C) HY < HZ < HX

126) D) HX < HZ < HY

127) What is the hydronium ion concentration of a 0.100 M hypochlorous acid solution with K a = 3.5 ˛ 10-8? The equation for the dissociation of hypochlorous acid is: HOCl( aq) + H2O( l) Ì H3 O+(aq) + OCl-(aq). A) 1.9 ˛ 10-5

B) 1.9 ˛ 10-4

C) 5.9 ˛ 10-5

127)

D) 5.9 ˛ 10-4

128) SO3 reacts with H2 O to form H2 SO4 . Which picture below correctly represents the curved arrow notation for the initial Lewis acid-Lewis base interaction in this reaction; what is the Lewis acid and the Lewis base?

128)

A) Picture (2) is correct; SO3 is the Lewis acid and H2 O is the Lewis base. B) Picture (2) is correct; H2 O is the Lewis acid and SO3 is the Lewis base. C) Picture (1) is correct; H2 O is the Lewis acid and SO3 is the Lewis base. D) Picture (1) is correct; SO3 is the Lewis acid and H2 O is the Lewis base. 129) Calculate the pH of a 0.100 M CH3 NH3 Cl solution. K b for methylamine, CH3 NH2 , is 3.7 ˛ 10-4. A) 5.78

B) 11.78

C) 8.22

D) 2.22

130) Which acid of the following set has the strongest conjugate base? A) HF

B) NH3

C) H2 O

23

129)

130) D) CH4

131) Para-Aminobenzoic acid (PABA), p-H2 NC6H4 (COOH), is used in some sunscreens and hair conditioning products. Calculate the pH of an aqueous solution with [PABA] = 0.030 M and K a = 2.2 ˛ 10-5. A) 6.18

B) 1.52

C) 4.66

D) 3.09

132) Which of the following BrMnsted-Lowry acids does not behave as a strong acid when it is dissolved in water? A) HBr

B) HCl

C) HClO4

131)

132)

D) HNO2

133) Write a balanced equation for the dissociation of the BrMnsted-Lowry acid HSO 4- in water.

133)

A) HSO4- (aq) + H2 O( l) Ì H2 SO4 (aq) + OH-(aq) B) HSO4- (aq) + H2 O( l) Ì SO3 ( g) + OH- (aq) + H2 O( l) C) HSO4- (aq) + H2 O( l) Ì SO4 2-(aq) + H3 O+(aq) D) HSO4- (aq) + H2 O( l) Ì SO3 2-(aq) + OH- (aq) 134) What is the pH of a solution prepared by mixing 100.00 mL of 0.020 M Ca(OH)2 with 50.00 mL of 0.100 M NaOH? Assume that the volumes are additive. A) 13.25

B) 12.78

C) 12.95

D) 12.67

135) What is the weakest acid among the following? A) H2 S

134)

135)

B) HCl

C) SiH 4

D) PH 3

136) What is the second stepwise equilibrium constant expression for phosphoric acid H3PO4? A) K a2 = ([H3O+][HPO 4 2-])/([H2 PO4- ])

B) K a2 = ([H3 O+]3[PO43-])/([H3PO4 ])

C) K a2 = ([H3O+]2[HPO4 2-])/([H3 PO4 ])

D) K a2 = ([H3 O+][H 2 PO4- ])/([H3 PO4 ])

136)


137) Arrange the conjugate bases (A- = X- , Y- , or Z- ) in order of increasing value of K b. A) K b(X- ) < K b(Z-) < K b(Y- )

B) K b(Y- ) < K b(Z- ) < K b(X- )

C) K b(Z- ) < K b(X-) < K b(Y- )

D) K b(Z- ) < K b(Y- ) < K b(X- )

138) What is the strongest acid among the following? A) H2 O

137)

138)

B) H2Te

C) H2 S 24

D) H2 Se

139) What is the hydronium ion concentration and the pH for an aqueous solution of NH3 that has a hydroxide ion concentration of 2.25 ˛ 10-3 M? A) 4.44 ˛ 10-12 M, 2.65 C) 4.44 ˛ 10-11 M, 3.65

139)

B) 4.44 ˛ 10-12 M, 11.35 D) 4.44 ˛ 10-11 M, 10.35


140) Arrange the acids in order of increasing pH. A) HY < HZ < HX

140)

B) HZ < HY < HX

C) HX < HZ < HY

D) HZ < HX < HY

141) BF3 and NH3 undergo a Lewis acid-base reaction forming an adduct. Which picture below correctly represents the curved arrow notation for the initial Lewis acid-Lewis base interaction in this reaction; what is the Lewis acid and the Lewis base?

A) Picture (2) is correct; BF3 is the Lewis acid and NH3 is the Lewis base. B) Picture (1) is correct; NH3 is the Lewis acid and BF3 is the Lewis base. C) Picture (4) is correct; BF3 is the Lewis acid and NH3 is the Lewis base. D) Picture (3) is correct; NH3 is the Lewis acid and BF3 is the Lewis base.

25

141)

142) What is the hydronium ion concentration and the pH for an aqueous solution of NH3 that has a hydroxide ion concentration of 2.25 ˛ 10-3 M? A) 4.44 ˛ 10-12 M and 11.35

B) 4.44 ˛ 10-11 M and 3.65

C) 4.44 ˛ 10-12 M and 2.65

D) 4.44 ˛ 10-11 M and 10.35

143) An Arrhenius base is best defined as a

142)

143)

A) substance that dissociates in water to produce aqueous hydroxide ions. B) hydroxide acceptor. C) substance that dissociates in water to produce aqueous hydrogen ions. D) proton donor. 144) Identify the Lewis acid that acts as a reactant in the following reaction Co(H 2 O)6 3+(aq) + 6 NH3 (aq) ¬ Co(NH 3)6 3+(aq) + 6 H2O( l). A) NH 3

B) Co(H2 O)6 3+

C) Co3+

144) D) H2 O

145) Which one of the following salts, when dissolved in water, produces the solution with a pHclosest to 7.00? A) NH 4 I

B) CsCl

C) Na2 O

146) Which one of the following is not considered to be a Lewis base? A) NH 3 B) NH4 + C) H2 O

D) KHCO 3 146) D) Cl-

147) What is the geometric shape of the hydrated proton; that is, the hydronium ion H3 O+? A) angular

B) tetrahedral

C) trigonal planar

B) NH4 Cl

C) AlCl3

147)

D) pyramidal

148) Which one of the following salts, when dissolved in water, produces the solution with thelowest pH? A) MgCl2

145)

148)

D) NaCl

149) What is the hydroxide ion concentration of a lye solution that has a pH of 10.20? A) 1.58 ˛ 10-4 M B) 6.31 ˛ 10-11 M C) 10.20 M D) 3.80 M

149)

150) What is the equilibrium constant expression (Ka ) for the acid dissociation of hydrocyanic acid HCN? The equation of interest is HCN(aq) + H2 O( l) Ì H3 O+(aq) + CN- (aq).

150)

A) K a = ([HCN][H2 O])/([H3 O+][CN -])

B) K a = ([HCN])/([H 3O+][CN- ])

C) K a = ([H3 O+][CN -])/([HCN][H 2 O])

D) K a = ([H3O+][CN- ])/([HCN])

151) What is the pH of a solution made by mixing 100.00 mL of 0.20 M HCl with 50.00 mL of 0.10 M HCl? Assume that the volumes are additive. A) 0.78

B) 1.70

C) 0.15

26

D) 0.52

151)

152) Which of the following salts are acidic?

152)

A) LiCl, NaCl, KCl

B) NaCH 3CO 2 , KCH3 CO 2 , RbCH3 CO 2

C) NH 4 Cl, CuCl 2 , AlCl3

D) NaCl, NH4 Cl, Na2 CO 3

153) Calculate the pH for an aqueous solution of acetic acid that contains 4.15 ˛ 10-3 M hydronium ion. A) 2.41 ˛ 10-12 M B) 11.62 C) 4.15 ˛ 10-3 M D) 2.38

153)

154) In the following chemical equation indicate the reactant that is a BrMnsted-Lowry acid HCN(aq) + H2 O( l) Ì H3 O+(aq) + CN- (aq).

154)

A) HCN

B) H3O+

C) CN-

D) H2 O

155) 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?

155)

A) neutral B) acidic C) basic D) There is insufficient information provided to answer this question. 156) Calculate the pH of a 0.100 M KBrO solution. K a for hypobromous acid, HBrO, is 2.0 ˛ 10-9. A) 4.85

B) 3.15

C) 10.85

D) 9.15

157) What is the pH of a 0.100 M NH3 solution that has K b = 1.8 ˛ 10-5 ? The equation for the dissociation of NH3 is NH 3(aq) + H2O( l) Ì NH4 +(aq) + OH- (aq)? A) 12.13

B) 1.87

C) 11.13

B) 6.67 ˛ 10-9 M, 5.82

C) 6.67 ˛ 10-9 M, 8.17

D) 6.67 ˛ 10-8 M, 7.18

159) Determine the acid dissociation constant for a 0.020 M formic acid solution that has a pH of 2.74. Formic acid is a weak monoprotic acid and the equilibrium equation of interest is HCOOH( aq) + H2 O( l) Ì H3 O+(aq) + HCO2- (aq). A) 1.8 ˛ 10-3

B) 1.8 ˛ 10-4

C) 3.6 ˛ 10-5

27

157)

D) 2.87

158) What is the hydroxide ion concentration and the pH for a hydrochloric acid solution that has a hydronium ion concentration of 1.50 ˛ 10-6 M? A) 6.67 ˛ 10-8 M, 6.82

156)

D) 3.6 ˛ 10-4

158)

159)


160) Identify the BrMnsted-Lowry bases. A) (2) and (4)

160)

B) (2) and (3)

C) (1) and (3)

D) (1) and (4)

161) What is the pH of a 0.040 M HClO4 solution? A) 0.080

161)

B) 0.040

C) 1.40

D) 12.60

162) Equal volumes of 0.10 M NH3 ( K b = 1.8 ˛ 10-5) and 0.10 M HCN (K a = 4.9 ˛ 10-10) are mixed together. Will the resulting solution be acidic, basic, or neutral? A) basic

B) acidic

C) neutral

D) insufficient information to solve

163) Which BrMnsted-Lowry acid is not considered to be a strong acid in water? A) HBr

B) H ClO4

C) HCl

162)

163) D) H NO2

164) Vinegar is a 5.0% solution by weight of acetic acid (CH3 COOH) in water. Given that K a = 1.8 ˛ 10-5 for acetic acid and assuming the density of vinegar to be 1.00 g/cm3 , what is the pH

164)

of this vinegar solution? A) 2.41

B) 2.00

C) 2.87

D) 4.74


165) Identify the BrMnsted-Lowry acid/base conjugate pairs. A) (1)/(3) and (2)/(4)

B) (1)/(4) and (2)/(3)

28

165) C) (1)/(2) and (3)/(4)

166) What is the pH of a 0.100 M NH3 solution that has K b = 1.8 ˛ 10-5? The equation for the dissociation of NH3 is NH 3 (aq) + H2 O( l) Ì NH4 +(aq) + OH- (aq). A) 12.13

B) 11.13

C) 1.87

D) 2.87

167) What is the conjugate acid of the BrMnsted-Lowry base HAsO4 2-? A) H2 O

B) H2AsO4 -

C) AsO43-

167) D) H3 O+

168) Calculate the pH of a 0.100 M NaCH3 CO 2 solution. K a for acetic acid, CH3 CO 2 H, is 1.8 ˛ 10-5. A) 2.87

B) 8.87

C) 5.13

166)

168)

D) 11.13

169) A tablet containing 500.0 mg of aspirin (acetylsalicyclic acid or HC9 H7O4 ) was dissolved in enough water to make 100 mL of solution. Given that K a = 3.0 ˛ 10-4 for aspirin, what is the pH of

169)

the solution? A) 1.57

B) 3.52

C) 5.08

D) 2.54

170) What is the strongest BrMnsted-Lowry acid in the chemical reaction shown below? 2 HNO3 (aq) + Ba(OH)2 (aq) ¬ Ba(NO3)2 (aq) + 2 H2 O(l) A) Ba(OH)2

B) HNO3

C) H2 O

D) Ba(NO3)2

171) Which one of the following salts, when dissolved in water, produces the solution with thehighest pH? A) KI

B) KF

C) KCl

170)

171)

D) KBr

172) Calculate the hydronium ion concentration in an aqueous solution that contains 2.50˛ 10-4 M in hydroxide ion. A) 5.00 ˛ 10-11 M B) 4.00 ˛ 10-10 M C) 4.00 ˛ 10-11 M D) 4.00 ˛ 10-9 M

172)

173) What is the strongest acid among the following?

173)

A) HIO4

B) HIO

C) HIO3

D) HIO2

174) What is the strongest monoprotic acid of the following set if all the acids are at 0.100 M concentration? A) hypochlorous acid with K a = 3.5 ˛ 10-8 B) benzoic acid with K a = 6.5 ˛ 10-5 C) acetic acid with K a = 1.8 ˛ 10-8

D) hydrofluoric acid with K a = 3.5 ˛ 10-4

29

174)


HIn π In-

pH range

Solution X

methyl orange

red-yellow

3.2-4.4

yellow

methyl red

red-yellow

4.8-6.0

yellow



6.0-7.6 8.2-10.0

B) 8.2 - 10.0

175)

green colorless

C) 3.2 - 4.4

D) 4.8 - 6.0

176) Calculate the pH for an aqueous solution of pyridine that contains 6.15 ˛ 10-4 M hydroxide ion. A) 10.79 B) 3.21 C) 1.63 ˛ 10-11 D) 6.15 ˛ 10-4

176)

177) An Arrhenius acid is best defined as a

177)

A) proton acceptor. B) substance that dissociates in water to produce aqueous hydrogen ions. C) hydroxide donor. D) substance that dissociates in water to produce aqueous hydroxide ions. 178) What is the equilibrium constant expression (K a ) for the acid dissociation of nitrous acid HNO2 ? The equation of interest is HNO2 (aq) + H2 O(l) Ì H3 O+(aq) + NO 2 - (aq). A) K a = ([H3 O+][NO 2 -])/([HNO2])

B) K a = ([H3O+][NO2 - ])/([HNO2 ][H 2 O])

C) K a = ([HNO2 ])/([H3 O+][NO2 -])

D) K a = ([HNO2 ][H 2O])/([H3 O+][NO2- ])


HIn π In-

pH range

Solution X

methyl orange

red-yellow

3.2-4.4

yellow

methyl red

red-yellow

4.8-6.0

yellow



6.0-7.6 8.2-10.0

B) 8.2 - 10.0

C) 4.8 - 6.0

B) 2.40

C) 2.10

30

179)

green colorless D) 7.6 - 8.2

180) What is the pH of a solution prepared by diluting 50.00 mL of 0.020 M Ba(OH)2 with enough water to produce a total volume of 250.00 mL? A) 11.90

178)

D) 11.60

180)

181) What is the pH of a 0.020 M HClO4 solution? A) 0.020

181)

B) 12.30

C) 1.70

D) 0.040

182) How many grams of pyridine are there in 100 mL of an aqueous solution that has a pH of 9.00? The K b for pyridine is 1.9 ˛ 10-9 and the equation of interest is C5 H5N(aq) + H2 O( l ) Ì C5H5NH +(aq) + OH-(aq). A) 7.9 g

B) 0.42 g

C) 0.053 g

D) 0.79 g

183) What is the pH of a 0.040 M Ba(OH)2 solution? A) 12.60

183)

B) 1.40

C) 13.90

D) 1.10

184) Aniline, (C6H5NH 2 , K b = 4.3 ˛ 10-10 at 25e C) is an industrially important amine used in the making of dyes. Determine the pH of an aniline solution made by dissolving 3.90 g of aniline in enough water to make 100 mL of solution. A) 9.13

182)

B) 4.87

C) 10.74

31

D) 9.74

184)

Answer Key Testname: CHEM 1B_CH15_PT.TST

1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 11) 12) 13) 14) 15) 16) 17) 18) 19) 20) 21) 22) 23) 24) 25) 26) 27) 28) 29) 30) 31) 32) 33) 34) 35) 36) 37) 38) 39) 40) 41) 42) 43) 44) 45) 46) 47) 48) 49) 50)

A A B A A B A A B A D B D B D B C B B A A A C C B C A A C D A A A A D C B C D D B C D B B B B D B B 1


51) 52) 53) 54) 55) 56) 57) 58) 59) 60) 61) 62) 63) 64) 65) 66) 67) 68) 69) 70) 71) 72) 73) 74) 75) 76) 77) 78) 79) 80) 81) 82) 83) 84) 85) 86) 87) 88) 89) 90) 91) 92) 93) 94) 95) 96) 97) 98) 99) 100)

A B B C D A D B B B A D A D B C B B C B D D B A D C C A A C C B A D B D C B A D D C D B A A B D A D 2


101) 102) 103) 104) 105) 106) 107) 108) 109) 110) 111) 112) 113) 114) 115) 116) 117) 118) 119) 120) 121) 122) 123) 124) 125) 126) 127) 128) 129) 130) 131) 132) 133) 134) 135) 136) 137) 138) 139) 140) 141) 142) 143) 144) 145) 146) 147) 148) 149) 150)

C A B A A B D C C B B A A B C C C C C B B B B D D C C A A D D D C B C A A B B C A A A C B B D C A D 3

Chem_1B_Ch15_PT

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