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1

A 1.50 L buffer solution is 0.250 M in HF and 0.250 M in NaF. Calculate the pH of the solution after the addition of 0.0500 moles of solid NaOH. Assume no volume change upon the addition of base. The Ka for HF is 3.5 × 10-4.

A)3.63

B)3.34

C)3.46

D)2.89

E)3.57

Answer: E

2

Which of the following acids is the WEAKEST? The acid is followed by its Ka value.

A)H COOH, 1.8 × 10-4

B)HNO2, 4.6 × 10-4

C)HClO2, 1.1 × 10-2

D)HF, 3.5 × 10-4

E)HCN, 4.9 × 10-10

Answer E

3

Calculate the pOH in an aqueous solution with a pH of 7.85 at 25°C.

A)5.15

B)7.15

C)6.15

D)8.15

E)4.15

Answer C

4

The pH of an aqueous solution at 25.0°C is 10.66. What is the molarity of H+ in this solution?

A)4.6 × 1010

B)4.6 × 10-4

C)2.2 × 10-11

D)1.1 × 10-13

E)3.3

Answer C

5

Consider a reaction that has a negative ΔH and a negative ΔS. Which of the following statements is TRUE?

A)This reaction will be nonspontaneous only at high temperatures.

B)This reaction will be nonspontaneous at all temperatures.

C)This reaction will be spontaneous at all temperatures.

D)This reaction will be spontaneous only at high temperatures.

E)It is not possible to determine without more information.

Answer A

6

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)5.5 × 10-10 M,neutral

B)1.8 × 10-10 M,basic

C)9.2 × 10-1 M, basic

D)1.8 × 10-10 M, acidic

E)9.2 × 10-1 M, acidic

Answer B

7

A buffer solution is 0.100 M in both HC7H5O2 and LiC7H5O2 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)5.69

B)4.49

C)3.69

D)3.89

E)There is not enough information to determine.

Answer B

8

Calculate the pH of a solution formed by mixing 150.0 mL of 0.10 M HC7H5O2 with 100.0 mL of 0.30 M NaC7H5O2. The Ka for HC7H5O2 is 6.5 × 10-5.

A)4.31

B)9.69

C)4.19

D)10.51

E)4.49

Answer E

9

Calculate the pH of a buffer that is 0.158 M HClO and 0.099 M NaClO. The Ka for HClO is 2.9 × 10-8.

A)3.77

B)7.54

C)6.67

D)6.46

E)7.33

Answer E

10

A 100.0 mL sample of 0.18 M HClO4 is titrated with 0.27 M LiOH. Determine the pH of the solution after the addition of 100.0 mL of LiOH.

A)0.87

B)12.6 5

C)12.95

D)13.13

E)1.35

Answer B

11

Calculate the pH of a solution formed by mixing 250.0 mL of 0.15 M HCHO2 with 100.0 mL of 0.20 M LiCHO2. The Ka for HCHO2 is 1.8 × 10-4.

A)10.13

B)3.87

C)3.47

D)10.53

E)3.74

Answer C

12

Calculate the pH of a solution that contains 3.9 x 10-5 M H3O+ at 25°C.

A)0.59

B)5.41

C)8.59

D)9.59

E)4.41

Answer E

13

Calculate the pH of a buffer that is 0.105 M HC2H3O2 and 0.146 M KC2H3O2. The Ka for HC2H3O2 is 1.8 × 10-5.

A)9.11

B)9.26

C)4.60

D)4.89

E)4.74

Answer D

14

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)5.62

E)8.38

Answer B

15

Which of the following acids will have the strongest conjugate base?

A)HClO4

B)HCN

C)HNO3

D)HCl

E)HI

Answer B

16

A 100.0 mL sample of 0.18 M HClO4 is titrated with 0.27 M LiOH. Determine the pH of the solution after the addition of 30.0 mL of LiOH.

A)1.12

B)2.86

C)1.21

D)2.00

E)0.86

Answer A

17

Determine the pH of a 0.023 M HNO3 solution.

A)12.36

B)2.30

C)1.64

D)2.49

E)3.68

Answer C

18

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

A)6.5 × 10-5 M

B)1.4 × 10-10 M

C)8.7 × 10-10 M

D)7.1 × 10-5 M

E)4.2 × 10-10 M

Answer D

19

Determine the [OH-] concentration of a 0.123 M Sr(OH)2 solution at 25°C.

A)0.0615 M

B)8.13 x 10-14 M

C)0.123 M

D)4.06 x 10-14 M

E)0.246 M

Answer E

20

Which of the following is a triprotic acid?

A)CCl4

B)H3PO4

C)H2SO4

D)HI

E)HC2H3O2

Answer B

21

Calculate the pOH of a solution that contains 7.8 x 10-6 M OH- at 25°C.

A)8.89

B)9.64

C)1.28

D)5.11

E)12.72

Answer D

22

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.

Answer B

23

Determine the molar solubility of Fe(OH)2 in pure water. Ksp for Fe(OH)2)= 4.87 × 10-17.

A)2.44 × 10-17 M

B)2.30 × 10-6 M

C)3.65 × 10-6 M

D)1.62 × 10-17 M

E)4.03 × 10-9 M

Answer B

24

Calculate the hydroxide ion concentration in an aqueous solution that contains 3.50 × 10-4 M in hydronium ion.

A)2.86 × 10-11 M

B)2.86 × 10-3 M

C)3.50 × 10-11 M

D)2.86 × 10-10 M

Answer A

25

A 1.00 L buffer solution is 0.250 M in HF and 0.250 M in LiF. Calculate the pH of the solution after the addition of 0.150 moles of solid LiOH. Assume no volume change upon the addition of base. The Ka for HF is 3.5 × 10-4.

A)4.24

B)4.06

C)3.46

D)3.63

E)2.85

Answer B

26

Calculate the pH of a buffer that is 0.058 M HF and 0.058 M LiF. The Ka for HF is 3.5 × 10-4.

A)10.54

B)9.31

C)4.69

D)3.46

E)2.86

Answer D

27

Which of the following is a polyprotic acid?

A)H2SO4

B)CCl4

C)HCN

D)HI

E)HC2H3O2

Answer A

28

Place the following in order of increasing acid strength.

HBrO2 HBrO3 HBrO HBrO4

A)HBrO2 < HBrO4 < HBrO < HBrO3

B)HBrO < HBrO2 < HBrO3 < HBrO4

C)HBrO4 < HBrO2 < HBrO3 < HBrO

D)HBrO2 < HBrO3 < HBrO4 < HBrO

E)HBrO < HBrO4 < HBrO3 < HBrO2

Answer B

29

What is the hydronium ion concentration of a 0.150 M hypochlorous acid solution with ka=3.5 x 10-8. The equation for the dissociation of hypochlorous acid is:

HOCl (aq)+ H2O (l)--> <-- H3O + (aq) + OCl- (aq)

A)7.2 × 10-4 M

B)1.9 × 10-4 M

C)7.2 × 10-5 M

D)2.8 × 10-5 M

Answer 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 NaOH

D)adding 0.050 moles of HCl

E)None of the above will destroy the buffer.

Answer D

31

Identify the weak diprotic acid.

A)HCOOH

B)CH3COOH

C)H2CO3

D)H3PO4

E)H2SO4

Answer C

32

Determine the Ka of an acid whose 0.294 M solution has a pH of 2.80.

A)5.4 × 10-3

B)8.5 × 10-6

C)1.2 × 10-5

D)4.9 × 10-7

E)2.7

Answer B

33

Identify the weakest acid.

A)HF

B)HI

C)HCl

D)HBr

E)not enough information is available

Answer A

34

Calculate the molarity of hydroxide ion in an aqueous solution that has a pOH of 5.00.

A)9.0 × 10-14

B)5.0 × 10-14

C)9.00

D)1.0 × 10-9

E)1.0 × 10-5

Answer E

35

Calculate the pH of a buffer that is 0.040 M HF and 0.020 M LiF. The Ka for HF is 3.5 × 10-4.

A)3.16

B)3.76

C)4.86

D)2.06

E)3.46

Answer A

36

A 100.0 mL sample of 0.10 M Ca(OH)2 is titrated with 0.10 M HBr. Determine the pH of the solution after the addition of 400.0 mL HBr.

A)2.11

B)1.22

C)1.00

D)1.40

E)1.30

Answer D

37

Identify the weak diprotic acid.

A)H3PO4

B)HClO4

C)H2SO3

D)H2SO4

E)HNO3

Answer C

38

You wish to prepare an HC2H3O2 buffer with a pH of 4.24. If the pKa of is 4.74, what ratio of C2H3O2 -/HC2H3O2 must you use?

A)0.32

B)2.8

C)0.10

D)0.50

E)2.0

Answer A

39

A 7.0 × 10-3 M aqueous solution of Ca(OH)2 at 25.0°C has a pH of ________.

A)1.85

B)12.15

C)11.85

D)1.4 × 10-2

E)7.1 × 10-13

Answer B

40

A 100.0 mL sample of 0.180 M HClO4 is titrated with 0.270 M LiOH. Determine the pH of the solution after the addition of 75.0 mL of LiOH.

A)2.65

B)1.89

C)12.1

D)13.06

E)11.35

Answer C

41

Calculate the pH for an aqueous solution of pyridine that contains 2.15 x 10-4 M hydroxide ion.

A)3.67

B)2.15 × 10-4

C)10.33

D)4.65 × 10-11

Answer C

42

Determine the molar solubility of BaF2 in a solution containing 0.0750 M LiF. Ksp (BaF2) = 1.7 × 10-6.

A)8.5 × 10-7 M

B)3.0 × 10-4 M

C)1.2 × 10-2 M

D)2.3 × 10-5 M

E)0.0750 M

Answer B

43

Determine the pOH of a 0.00598 M HClO4 solution.

A)11.777

B)2.223

C)6.434

D)7.566

E)3.558

Answer A

44

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

Answer E

45

The molar solubility of Ag2S is 1.26 × 10-16 M in pure water. Calculate the Ksp for Ag2S.

A)6.81 × 10-63

B)3.78 × 10-12

C)8.00 × 10-48

D)1.12 × 10-8

E)1.59 × 10-32

Answer C

46

Calculate the pH of a solution formed by mixing 100.0 mL of 0.20 M HClO with 200.0 mL of 0.30 M KClO. The Ka for HClO is 2.9 × 10-8.

A)7.06

B)6.46

C)5.99

D)8.01

E)7.54

Answer D

47

A 100.0 mL sample of 0.18 M HClO4 is titrated with 0.27 M LiOH. Determine the pH of the solution after the addition of 66.67 mL of LiOH (this is the equivalence point).

A)7.00

B)2.76

C)11.24

D)13.03

E)0.97

Answer A

48

Calculate the pH of a buffer that is 0.225 M HC2H3O2 and 0.162 M KC2H3O2. The Ka for HC2H3O2 is 1.8 × 10-5.

A)4.74

B)4.89

C)9.26

D)9.11

E)4.60

Answer E

49

What is the hydronium ion concentration of a 0.500 M acetic acid solution with K a = 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)3.0 × 10-3 M

C)4.2 × 10-3 M

D)4.2 × 10-2 M

Answer B

50

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

Answer C