Question 1

An acetate buffer has a pH of 4.40. Which of the following changes will cause the pH to decrease?

Accepted Answer

A)  Dissolving a small amount of solid sodium acetate
B)  Ading a small amount of dilute hydrochloric acid
C)  Adding a small amount of dilute sodium hydroxide
D)  Dissolving a small amount of solid sodium chloride
E)  Diluting the buffer solution with waterF) B) and D)
G) A) and E)

Question 2

A buffer is prepared by adding 150 mL of 1.0 M NaOH to 250 mL of 1.0 M NaH2PO4. How many moles of HCl must be added to this buffer solution to change the pH by 0.18 units? If necessary, assume the total volume remains unchanged at 400 mL.

Accepted Answer

A)  0.025 mol HCl
B)  0.063 mol HCl
C)  0.082 mol HCl
D)  0.50 mol HCl
E)  1.0 mol HClF) C) and D)
G) B) and E)

Question 3

Which of the following substances has the greatest solubility in water?

Accepted Answer

A)  PbI 2, K sp = 7.9 × 10 −9
B)  BaF 2, K sp = 1.5 × 10 −6
C)  Ca(OH) 2, K sp = 6.5 × 10 −6
D)  Zn(IO 3) 2, K sp = 3.9 × 10 −6
E)  Ag 2SO 4, K sp = 1.5 × 10 −5F) A) and D)
G) B) and D)

Question 4

What is the [H3O+] in a solution that consists of 0.15 M C2N2H8 (ethylene diamine)  and 0.35 C2N2H9Cl? Kb = 4.7 × 10−4

Accepted Answer

A)  2.0 × 10 −3  M
B)  1.1 × 10 −3 M
C)  6.3 × 10 −9  M
D)  2.1 × 10 −10  M
E)  5.0 × 10 −11  MF) C) and D)
G) B) and E)

Question 5

A 20.0-mL sample of 0.25 M HNO3 is titrated with 0.15 M NaOH. What is the pH of the solution after 30.0 mL of NaOH have been added to the acid?

Accepted Answer

A)  2.00
B)  1.60
C)  1.05
D)  1.00
E)  None of these choices are correct.F) All of the above
G) A) and B)

Question 6

What volume of 0.500 M H2SO4 is needed to react completely with 20.0 mL of 0.400 M LiOH?

Accepted Answer

A)  4.00 mL
B)  8.00 mL
C)  12.5 mL
D)  16.0 mL
E)  32.0 mLF) C) and D)
G) B) and E)

Question 7

The concentration of the complex ion in each of following solutions is 1.00 M. In which of the solutions will the concentration of the uncomplexed metal ion be the greatest? Hg(CN) 42− Kf = 9.3 × 1038
Be(OH) 42− Kf = 4.0 × 1018
Zn(OH) 42− Kf = 3.0 × 1015
Cu(NH3) 42+ Kf = 5.6 × 1011
CdI42− Kf = 1.0 × 106

Accepted Answer

A)  Hg 2+
B)  Be 2+
C)  Zn 2+
D)  Cu 2+
E)  Cd 2+F) C) and D)
G) B) and C)

Question 8

Which of the following aqueous mixtures would be a buffer system?

Accepted Answer

A)  HCl, NaCl
B)  HNO 3, NaNO 3
C)  H 3PO 4, H 2PO 4 −
D)  H 2SO 4, CH 3COOH
E)  NH 3, NaOHF) A) and B)
G) A) and C)

Question 9

The solubility of silver chromate is 0.0287 g/1.0 L of solution. What is the Ksp for Ag2CrO4?

Accepted Answer

A)  9.5 × 10 −5
B)  2.4 × 10 −5
C)  2.6 × 10 −12
D)  6.5 × 10 −13
E)  −13F) A) and E)
G) C) and D)

Question 10

What is the pH of a buffer that consists of 0.45 M CH3COOH and 0.35 M CH3COONa? Ka = 1.8 × 10−5

Accepted Answer

A)  4.49
B)  4.64
C)  4.85
D)  5.00
E)  5.52F) C) and D)
G) None of the above

Question 11

The lab technician Anna Lytic adds 2.20 mol KOH to 1.00 L of 0.5 M Al(NO3) 3. What is the concentration of aluminum ions after the aluminum nitrate has reacted with the potassium hydroxide? Kf = 3.0 × 1033 for Al(OH) 4−

Accepted Answer

A)  1.8 × 10 −7 M
B)  9.1 × 10 −18 M
C)  1.0 × 10 −31 M
D)  3.3 × 10 −34 M
E)  7.1 × 10 −36 MF) A) and D)
G) B) and D)

Question 12

Two buffer solutions are prepared using acetic acid and sodium acetate. Solution A contains 20.0 g of acetic acid (CH3COOH)  and 5.0 g of sodium acetate CH3COONa) . Solution B contains 10.0 g of acetic acid and 25.0 g of sodium acetate. What is the difference between the pH values of these two solutions? For acetic acid, Ka = 1.8 × 10−5.

Accepted Answer

A)  0.0
B)  1.0
C)  2.0
D)  2.3
E)  4.6F) C) and E)
G) A) and D)

Question 13

A 10.0-mL sample of 0.75 M CH3CH2COOH is titrated with 0.30 M NaOH. What is the pH of the solution after 22.0 mL of NaOH have been added to the acid? Ka = 1.3 × 10−5

Accepted Answer

A)  5.75
B)  4.94
C)  4.83
D)  4.02
E)  3.95F) B) and E)
G) A) and D)

Question 14

A solution is prepared by adding 500 mL of 0.3 M NaClO to 500 mL of 0.4 M HClO. What is the pH of this solution?

Accepted Answer

A)  The pH will be greater than the pK a of hypochlorous acid.
B)  The pH will be less than the pK a of hypochlorous acid.
C)  The pH will be equal to the pK a of hypochlorous acid.
D)  The pH will equal the pK b of sodium hypochlorite.
E)  None of these choices are correct.F) A) and C)
G) A) and B)

Question 15

What volume of 0.200 M KOH must be added to 17.5 mL of 0.135 M H3PO4 to reach the third equivalence point?

Accepted Answer

A)  3.94 mL
B)  11.8 mL
C)  17.5 mL
D)  23.6 mL
E)  35.4 mLF) All of the above
G) A) and D)

Question 16

If the pH of a buffer solution is greater than the pKa value of the buffer acid, the buffer will have more capacity to neutralize added base than added acid.

Accepted Answer

A) True 
 B)False

Question 17

A buffer is to be prepared by adding solid sodium acetate to 0.10 M CH3COOH. Which of the following concentrations of sodium acetate will produce the most effective buffer?

Accepted Answer

A)  3.0 M CH 3COONa
B)  2.5 M CH 3COONa
C)  2.0 M CH 3COONa
D)  1.5 M CH 3COONa
E)  0.30 M CH 3COONaF) B) and D)
G) A) and B)

Question 18

Increasing the concentrations of the components of a buffer solution will increase the buffer range.

Accepted Answer

A) True 
 B)False

Question 19

You need to use KH2PO4 and K2HPO4 to prepare a buffer with a pH of 7.45. Which of the following ratios of [base]/[acid] is required? For phosphoric acid, (H3PO4) , Ka2 = 6.2 × 10−8.

Accepted Answer

A)  [base]/[acid] = 1.75
B)  [base]/[acid] = 1.27
C)  [base]/[acid] = 1.24
D)  [base]/[acid] = 0.79
E)  [base]/[acid] = 0.57F) A) and E)
G) A) and B)

Question 20

What will be the effect of adding 0.5 mL of 0.1 M HCl to 100 mL of a phosphate buffer in which [H2PO4−] = [HPO42−] = 0.35 M?

Accepted Answer

A)  The pH will increase slightly.
B)  The pH will increase significantly.
C)  The pH will decrease slightly.
D)  The pH will decrease significantly.
E)  Since it is a buffer solution, the pH will not be affected.F) B) and D)
G) None of the above

Exam 19: Ionic Equilibria in Aqueous Systems

A solution is prepared by adding 500 mL of 0.3 M NaClO to 500 mL of 0.4 M HClO. What is the pH of this solution?

Correct Answer
verified

A 20.0-mL sample of 0.25 M HNO₃is titrated with 0.15 M NaOH. What is the pH of the solution after 30.0 mL of NaOH have been added to the acid?

Correct Answer
verified

What is the pH of a buffer that consists of 0.45 M CH₃COOH and 0.35 M CH₃COONa? K_a = 1.8 × 10⁻⁵

Correct Answer
verified

A 10.0-mL sample of 0.75 M CH₃CH₂COOH is titrated with 0.30 M NaOH. What is the pH of the solution after 22.0 mL of NaOH have been added to the acid? K_a = 1.3 × 10⁻⁵

Correct Answer
verified

Which of the following substances has the greatest solubility in water?

Correct Answer
verified

Increasing the concentrations of the components of a buffer solution will increase the buffer range.

Correct Answer
verified

If the pH of a buffer solution is greater than the pK_a value of the buffer acid, the buffer will have more capacity to neutralize added base than added acid.

Correct Answer
verified

An acetate buffer has a pH of 4.40. Which of the following changes will cause the pH to decrease?

Correct Answer
verified

What will be the effect of adding 0.5 mL of 0.1 M HCl to 100 mL of a phosphate buffer in which [H₂PO₄⁻] = [HPO₄²⁻] = 0.35 M?

Correct Answer
verified

The lab technician Anna Lytic adds 2.20 mol KOH to 1.00 L of 0.5 M Al(NO₃) ₃. What is the concentration of aluminum ions after the aluminum nitrate has reacted with the potassium hydroxide? K_f= 3.0 × 10³³ for Al(OH) ₄⁻

Correct Answer
verified

What is the [H₃O⁺] in a solution that consists of 0.15 M C₂N₂H₈(ethylene diamine) and 0.35 C₂N₂H₉Cl? K_b = 4.7 × 10⁻⁴

Correct Answer
verified

Correct Answer
verified

A buffer is to be prepared by adding solid sodium acetate to 0.10 M CH₃COOH. Which of the following concentrations of sodium acetate will produce the most effective buffer?

Correct Answer
verified

A buffer is prepared by adding 150 mL of 1.0 M NaOH to 250 mL of 1.0 M NaH₂PO₄. How many moles of HCl must be added to this buffer solution to change the pH by 0.18 units? If necessary, assume the total volume remains unchanged at 400 mL.

Correct Answer
verified

The solubility of silver chromate is 0.0287 g/1.0 L of solution. What is the K_sp for Ag₂CrO₄?

Correct Answer
verified

What volume of 0.200 M KOH must be added to 17.5 mL of 0.135 M H₃PO₄to reach the third equivalence point?

Correct Answer
verified

What volume of 0.500 M H₂SO₄is needed to react completely with 20.0 mL of 0.400 M LiOH?

Correct Answer
verified

Which of the following aqueous mixtures would be a buffer system?

Correct Answer
verified

Correct Answer
verified

You need to use KH₂PO₄ and K₂HPO₄ to prepare a buffer with a pH of 7.45. Which of the following ratios of [base]/[acid] is required? For phosphoric acid, (H₃PO₄) , K_a2 = 6.2 × 10⁻⁸.

Correct Answer
verified

Exam 19: Ionic Equilibria in Aqueous Systems

A solution is prepared by adding 500 mL of 0.3 M NaClO to 500 mL of 0.4 M HClO. What is the pH of this solution?

Correct AnswerverifiedShow Answer

A 20.0-mL sample of 0.25 M HNO3 is titrated with 0.15 M NaOH. What is the pH of the solution after 30.0 mL of NaOH have been added to the acid?

Correct AnswerverifiedShow Answer

What is the pH of a buffer that consists of 0.45 M CH3COOH and 0.35 M CH3COONa? Ka = 1.8 × 10−5

Correct AnswerverifiedShow Answer

A 10.0-mL sample of 0.75 M CH3CH2COOH is titrated with 0.30 M NaOH. What is the pH of the solution after 22.0 mL of NaOH have been added to the acid? Ka = 1.3 × 10−5

Correct AnswerverifiedShow Answer

Which of the following substances has the greatest solubility in water?

Correct AnswerverifiedShow Answer

Increasing the concentrations of the components of a buffer solution will increase the buffer range.

Correct AnswerverifiedShow Answer

If the pH of a buffer solution is greater than the pKa value of the buffer acid, the buffer will have more capacity to neutralize added base than added acid.

Correct AnswerverifiedShow Answer

An acetate buffer has a pH of 4.40. Which of the following changes will cause the pH to decrease?

Correct AnswerverifiedShow Answer

What will be the effect of adding 0.5 mL of 0.1 M HCl to 100 mL of a phosphate buffer in which [H2PO4−] = [HPO42−] = 0.35 M?

Correct AnswerverifiedShow Answer

The lab technician Anna Lytic adds 2.20 mol KOH to 1.00 L of 0.5 M Al(NO3) 3. What is the concentration of aluminum ions after the aluminum nitrate has reacted with the potassium hydroxide? Kf = 3.0 × 1033 for Al(OH) 4−

Correct AnswerverifiedShow Answer

What is the [H3O+] in a solution that consists of 0.15 M C2N2H8 (ethylene diamine) and 0.35 C2N2H9Cl? Kb = 4.7 × 10−4

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

A buffer is to be prepared by adding solid sodium acetate to 0.10 M CH3COOH. Which of the following concentrations of sodium acetate will produce the most effective buffer?

Correct AnswerverifiedShow Answer

A buffer is prepared by adding 150 mL of 1.0 M NaOH to 250 mL of 1.0 M NaH2PO4. How many moles of HCl must be added to this buffer solution to change the pH by 0.18 units? If necessary, assume the total volume remains unchanged at 400 mL.

Correct AnswerverifiedShow Answer

The solubility of silver chromate is 0.0287 g/1.0 L of solution. What is the Ksp for Ag2CrO4?

Correct AnswerverifiedShow Answer

What volume of 0.200 M KOH must be added to 17.5 mL of 0.135 M H3PO4 to reach the third equivalence point?

Correct AnswerverifiedShow Answer

What volume of 0.500 M H2SO4 is needed to react completely with 20.0 mL of 0.400 M LiOH?

Correct AnswerverifiedShow Answer

Which of the following aqueous mixtures would be a buffer system?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

You need to use KH2PO4 and K2HPO4 to prepare a buffer with a pH of 7.45. Which of the following ratios of [base]/[acid] is required? For phosphoric acid, (H3PO4) , Ka2 = 6.2 × 10−8.

Correct AnswerverifiedShow Answer

Correct Answer
verified

A 20.0-mL sample of 0.25 M HNO₃is titrated with 0.15 M NaOH. What is the pH of the solution after 30.0 mL of NaOH have been added to the acid?

Correct Answer
verified

What is the pH of a buffer that consists of 0.45 M CH₃COOH and 0.35 M CH₃COONa? K_a = 1.8 × 10⁻⁵

Correct Answer
verified

A 10.0-mL sample of 0.75 M CH₃CH₂COOH is titrated with 0.30 M NaOH. What is the pH of the solution after 22.0 mL of NaOH have been added to the acid? K_a = 1.3 × 10⁻⁵

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

If the pH of a buffer solution is greater than the pK_a value of the buffer acid, the buffer will have more capacity to neutralize added base than added acid.

Correct Answer
verified

Correct Answer
verified

What will be the effect of adding 0.5 mL of 0.1 M HCl to 100 mL of a phosphate buffer in which [H₂PO₄⁻] = [HPO₄²⁻] = 0.35 M?

Correct Answer
verified

The lab technician Anna Lytic adds 2.20 mol KOH to 1.00 L of 0.5 M Al(NO₃) ₃. What is the concentration of aluminum ions after the aluminum nitrate has reacted with the potassium hydroxide? K_f= 3.0 × 10³³ for Al(OH) ₄⁻

Correct Answer
verified

What is the [H₃O⁺] in a solution that consists of 0.15 M C₂N₂H₈(ethylene diamine) and 0.35 C₂N₂H₉Cl? K_b = 4.7 × 10⁻⁴

Correct Answer
verified

Correct Answer
verified

A buffer is to be prepared by adding solid sodium acetate to 0.10 M CH₃COOH. Which of the following concentrations of sodium acetate will produce the most effective buffer?

Correct Answer
verified

A buffer is prepared by adding 150 mL of 1.0 M NaOH to 250 mL of 1.0 M NaH₂PO₄. How many moles of HCl must be added to this buffer solution to change the pH by 0.18 units? If necessary, assume the total volume remains unchanged at 400 mL.

Correct Answer
verified

The solubility of silver chromate is 0.0287 g/1.0 L of solution. What is the K_sp for Ag₂CrO₄?

Correct Answer
verified

What volume of 0.200 M KOH must be added to 17.5 mL of 0.135 M H₃PO₄to reach the third equivalence point?

Correct Answer
verified

What volume of 0.500 M H₂SO₄is needed to react completely with 20.0 mL of 0.400 M LiOH?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

You need to use KH₂PO₄ and K₂HPO₄ to prepare a buffer with a pH of 7.45. Which of the following ratios of [base]/[acid] is required? For phosphoric acid, (H₃PO₄) , K_a2 = 6.2 × 10⁻⁸.

Correct Answer
verified