Question 1

The pH of a solution that is 0.20 M CH3COOH and 0.20 M CH3COONa should be higher than the pH of a 0.20 M CH3COOH solution.

Accepted Answer

A) True 
 B)False

Question 2

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

Accepted Answer

A) True 
 B)False

Question 3

What is the pH of a buffer that consists of 0.20 M NaH2PO4 and 0.40 M Na2HPO4? [Ka(NaH2PO4) = 6.2 × 10-8]

Accepted Answer

A)  6.51 
B)  6.91 
C)  7.51 
D)  7.90 
E)  8.13 
A)  6.51 
B)  6.91 
C)  7.51 
D)  7.90 
E)  8.13

Question 4

40.0 ml of an acetic acid solution of unknown concentration is titrated with 0.100 M NaOH. After 20.0 mL of the base solution has been added, the pH in the titration flask is 5.10. What was the concentration of the original acetic acid solution? (Ka(CH3COOH) = 1.8 × 10-5)

Accepted Answer

A)  0.11 M 
B)  0.022 M 
C)  0.072 M 
D)  0.050 M 
E)  0.015 M 
A)  0.11 M 
B)  0.022 M 
C)  0.072 M 
D)  0.050 M 
E)  0.015 M

Question 5

Which of the following is correct for the equivalence point in an acid-base titration?

Accepted Answer

A)  The pH is at its highest value for any reaction. 
B)  The amounts of acid and base combined are in a stoichiometric ratio at the equivalence point in an acid-base titration. 
C)  The pH is 7.0. 
D)  The pH is equal to the pKa of the weak acid. 
E)  The pH is equal to the pKb of the weak base. 
A)  The pH is at its highest value for any reaction. 
B)  The amounts of acid and base combined are in a stoichiometric ratio at the equivalence point in an acid-base titration. 
C)  The pH is 7.0. 
D)  The pH is equal to the pKa of the weak acid. 
E)  The pH is equal to the pKb of the weak base.

Question 6

________ is the way to identify the types of ions in a solution using selective precipitation.

Accepted Answer

Qualitativ

Question 7

When a strong acid is titrated with a weak base, the pH at the equivalence point

Accepted Answer

A)  is greater than 7.0. 
B)  is equal to 7.0. 
C)  is less than 7.0. 
D)  is equal to the pKa of the conjugate acid. 
E)  is equal to the pKb of the base. 
A)  is greater than 7.0. 
B)  is equal to 7.0. 
C)  is less than 7.0. 
D)  is equal to the pKa of the conjugate acid. 
E)  is equal to the pKb of the base.

Question 8

Which pair of substances cannot form a buffered aqueous solution?

Accepted Answer

A)  HCN and KCN 
B)  NH3 and (NH4)2SO4 
C)  HNO3 and NaNO3 
D)  HF and NaF 
E)  HNO2 and NaNO2 
A)  HCN and KCN 
B)  NH3 and (NH4)2SO4 
C)  HNO3 and NaNO3 
D)  HF and NaF 
E)  HNO2 and NaNO2

Question 9

A solution is prepared by mixing 50.0 mL of 0.50 M Cu(NO3)2 with 50.0 mL of 0.50 M Co(NO3)2. Sodium hydroxide is slowly added to the mixture. Which precipitates first? [Ksp(Cu(OH)2) = 2.2 × 10-20, Ksp(Co(OH)2) = 1.3 × 10-15]

Accepted Answer

A)  Co(OH)2 
B)  Co(NO3)2 
C)  Cu(NO3)2 
D)  Cu(OH)2 
E)  No precipitate is formed. 
A)  Co(OH)2 
B)  Co(NO3)2 
C)  Cu(NO3)2 
D)  Cu(OH)2 
E)  No precipitate is formed.

Question 10

Which best describes the pH at the equivalence point of a titration of a weak acid with a strong base?

Accepted Answer

A)  Less than zero 
B)  Between 0 and 7 
C)  Close to 7.0 
D)  Between 7 and 14 
E)  Greater than 14 
A)  Less than zero 
B)  Between 0 and 7 
C)  Close to 7.0 
D)  Between 7 and 14 
E)  Greater than 14

Question 11

If 50.0 mL of 1.2 × 10-3 M Pb(NO3)2 are added to 50.0 mL of 2.0 × 10-4 M Na2S, what takes place?

Accepted Answer

A)  A precipitate of PbS forms. 
B)  A precipitate of NaNO3 forms. 
C)  A precipitate of Na2S forms. 
D)  A precipitate of Pb(NO3)2 forms. 
E)  No precipitate forms. 
A)  A precipitate of PbS forms. 
B)  A precipitate of NaNO3 forms. 
C)  A precipitate of Na2S forms. 
D)  A precipitate of Pb(NO3)2 forms. 
E)  No precipitate forms.

Question 12

Which cation would form an insoluble chloride when reacted with HCl?

Accepted Answer

A)  Na+ 
B)  Ag+ 
C)  B3+ 
D)  Ca2+ 
E)  Cs+ 
A)  Na+ 
B)  Ag+ 
C)  B3+ 
D)  Ca2+ 
E)  Cs+

Question 13

Does a precipitate of magnesium fluoride form if 300.0 mL of 1.1 × 10-3 M MgCl2 are added to 500.0 mL of 1.2 × 10-3 M NaF? [Ksp(MgF2) = 6.9 × 10-9]

Accepted Answer

A)  Yes, because Q > Ksp. 
B)  No, because Q sp. 
C)  No, because Q = Ksp. 
D)  Yes, because Q sp. 
E)  No, because Q > Ksp. 
A)  Yes, because Q > Ksp. 
B)  No, because Q sp. 
C)  No, because Q = Ksp. 
D)  Yes, because Q sp. 
E)  No, because Q > Ksp.

Question 14

Calculate the pH of the solution resulting from the addition of 10.0 mL of 0.10 M NaOH to 50.0 mL of 0.10 M HCN (Ka = 4.9 × 10-10) solution.

Accepted Answer

A)  5.15 
B)  8.71 
C)  5.85 
D)  9.91 
E)  13.0 
A)  5.15 
B)  8.71 
C)  5.85 
D)  9.91 
E)  13.0

Question 15

What is the pH of a solution that is 0.410 M in HOCl and 0.050 M in NaOCl? [Ka(HOCl) = 3.2 × 10-8]

Accepted Answer

A)  0.39 
B)  3.94 
C)  6.58 
D)  7.49 
E)  8.40 
A)  0.39 
B)  3.94 
C)  6.58 
D)  7.49 
E)  8.40

Question 16

Which is included in the Ksp expression? I. Concentration of cation
II) Concentration of anion
III) Concentration of solid

Accepted Answer

A)  I only 
B)  II only 
C)  III only 
D)  I and II 
E)  I, II and III 
A)  I only 
B)  II only 
C)  III only 
D)  I and II 
E)  I, II and III

Question 17

Propanoic acid (CH3CH2COOH) has a Ka of 1.34 × 10-5. A 25.00-mL sample of 0.1000 mol • L-1 propanoic acid (in flask) is titrated with 0.1000 mol • L-1 NaOH solution, added from a buret. Carry out the calculations of the quantities indicated below.
a. The pH after 0.00 mL of NaOH is added.
b. The pH after 15.00 mL of NaOH is added.

Accepted Answer

Question 18

What is the name of the principle of selective precipitation used to identify the types of ions present in a solution?

Accepted Answer

A)  Ionization 
B)  Selective ion precipitation 
C)  Selective ion typing 
D)  Limited precipitation 
E)  Qualitative analysis 
A)  Ionization 
B)  Selective ion precipitation 
C)  Selective ion typing 
D)  Limited precipitation 
E)  Qualitative analysis

Question 19

What is the pH of a buffer solution prepared by dissolving 0.20 mole of cyanic acid (HCNO) and 0.80 mole of sodium cyanate (NaCNO) in enough water to make 1.0 liter of solution? [Ka(HCNO) = 2.0 × 10-4]

Accepted Answer

A)  0.97 
B)  3.10 
C)  4.40 
D)  3.70 
E)  4.30 
A)  0.97 
B)  3.10 
C)  4.40 
D)  3.70 
E)  4.30

Question 20

The solubility of lead(II) chloride is 0.45 g/100 mL of solution. What is the Ksp of PbCl2?

Accepted Answer

A)  4.9 × 10-2 
B)  1.7 × 10-5 
C)  8.5 × 10-6 
D)  4.2 × 10-6 
E)  2.6 × 10-4 
A)  4.9 × 10-2 
B)  1.7 × 10-5 
C)  8.5 × 10-6 
D)  4.2 × 10-6 
E)  2.6 × 10-4

Exam 17: Acid-Base Equilibria and Solubility Equilibria

The pH of a solution that is 0.20 M CH3COOH and 0.20 M CH3COONa should be higher than the pH of a 0.20 M CH3COOH solution.

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

What is the pH of a buffer that consists of 0.20 M NaH2PO4 and 0.40 M Na2HPO4? [Ka(NaH2PO4) = 6.2 × 10-8]

40.0 ml of an acetic acid solution of unknown concentration is titrated with 0.100 M NaOH. After 20.0 mL of the base solution has been added, the pH in the titration flask is 5.10. What was the concentration of the original acetic acid solution? (Ka(CH3COOH) = 1.8 × 10-5)

Which of the following is correct for the equivalence point in an acid-base titration?

________ is the way to identify the types of ions in a solution using selective precipitation.

When a strong acid is titrated with a weak base, the pH at the equivalence point

Which pair of substances cannot form a buffered aqueous solution?

A solution is prepared by mixing 50.0 mL of 0.50 M Cu(NO3)2 with 50.0 mL of 0.50 M Co(NO3)2. Sodium hydroxide is slowly added to the mixture. Which precipitates first? [Ksp(Cu(OH)2) = 2.2 × 10-20, Ksp(Co(OH)2) = 1.3 × 10-15]

Which best describes the pH at the equivalence point of a titration of a weak acid with a strong base?

If 50.0 mL of 1.2 × 10-3 M Pb(NO3)2 are added to 50.0 mL of 2.0 × 10-4 M Na2S, what takes place?

Which cation would form an insoluble chloride when reacted with HCl?

Does a precipitate of magnesium fluoride form if 300.0 mL of 1.1 × 10-3 M MgCl2 are added to 500.0 mL of 1.2 × 10-3 M NaF? [Ksp(MgF2) = 6.9 × 10-9]

Calculate the pH of the solution resulting from the addition of 10.0 mL of 0.10 M NaOH to 50.0 mL of 0.10 M HCN (Ka = 4.9 × 10-10) solution.

What is the pH of a solution that is 0.410 M in HOCl and 0.050 M in NaOCl? [Ka(HOCl) = 3.2 × 10-8]

Which is included in the Ksp expression? I. Concentration of cation II) Concentration of anion III) Concentration of solid

What is the name of the principle of selective precipitation used to identify the types of ions present in a solution?

What is the pH of a buffer solution prepared by dissolving 0.20 mole of cyanic acid (HCNO) and 0.80 mole of sodium cyanate (NaCNO) in enough water to make 1.0 liter of solution? [Ka(HCNO) = 2.0 × 10-4]

The solubility of lead(II) chloride is 0.45 g/100 mL of solution. What is the Ksp of PbCl2?

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Intermolecular Forces and the Physical Properties of Liquids and Solids

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Filters

The pH of a solution that is 0.20 M CH₃COOH and 0.20 M CH₃COONa should be higher than the pH of a 0.20 M CH₃COOH solution.

What is the pH of a buffer that consists of 0.20 M NaH₂PO₄ and 0.40 M Na₂HPO₄? [K_a(NaH₂PO₄) = 6.2 × 10^-8]

40.0 ml of an acetic acid solution of unknown concentration is titrated with 0.100 M NaOH. After 20.0 mL of the base solution has been added, the pH in the titration flask is 5.10. What was the concentration of the original acetic acid solution? (K_a(CH₃COOH) = 1.8 × 10^-5)

A solution is prepared by mixing 50.0 mL of 0.50 M Cu(NO₃)₂ with 50.0 mL of 0.50 M Co(NO₃)₂. Sodium hydroxide is slowly added to the mixture. Which precipitates first? [K_sp(Cu(OH)₂) = 2.2 × 10^-20, K_sp(Co(OH)₂) = 1.3 × 10^-15]

If 50.0 mL of 1.2 × 10^-3^MPb(NO₃)₂ are added to 50.0 mL of 2.0 × 10^-4^M Na₂S, what takes place?

Does a precipitate of magnesium fluoride form if 300.0 mL of 1.1 × 10^-3^M MgCl₂ are added to 500.0 mL of 1.2 × 10^-3^MNaF? [K_sp(MgF₂) = 6.9 × 10^-9]

Calculate the pH of the solution resulting from the addition of 10.0 mL of 0.10 M NaOH to 50.0 mL of 0.10 M HCN (K_a = 4.9 × 10^-10) solution.

What is the pH of a solution that is 0.410 M in HOCl and 0.050 M in NaOCl? [K_a(HOCl) = 3.2 × 10^-8]

Which is included in the K_sp expression? I. Concentration of cation II) Concentration of anion III) Concentration of solid

What is the pH of a buffer solution prepared by dissolving 0.20 mole of cyanic acid (HCNO) and 0.80 mole of sodium cyanate (NaCNO) in enough water to make 1.0 liter of solution? [K_a(HCNO) = 2.0 × 10^-4]

The solubility of lead(II) chloride is 0.45 g/100 mL of solution. What is the K_sp of PbCl₂?