Question 1

The acid dissociation constant Ka equals 1.26 *10¯2 for HSO4¯ and is 5.6 *10¯10 for NH4+. Which statement about the following equilibrium is correct? a equals 1.26 *10¯2 for HSO4¯ and is 5.6 *10¯10 for NH4+. Which statement about the following equilibrium is correct?   A)  The reactants will be favored because ammonia is a stronger base than the sulfate anion. B)  The products will be favored because the hydrogen sulfate ion is a stronger acid than the ammonium ion. C)  Neither reactants nor products will be favored because all of the species are weak acids or bases. D)  The initial concentrations of the hydrogen sulfate ion and ammonia must be known before any prediction can be made. E)  This reaction is impossible to predict, since the strong acid and the weak base appear on the same side of the equation." class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   The reactants will be favored because ammonia is a stronger base than the sulfate anion.
B)   The products will be favored because the hydrogen sulfate ion is a stronger acid than the ammonium ion.
C)   Neither reactants nor products will be favored because all of the species are weak acids or bases.
D)   The initial concentrations of the hydrogen sulfate ion and ammonia must be known before any prediction can be made.
E)   This reaction is impossible to predict, since the strong acid and the weak base appear on the same side of the equation.F) B) and D)
G) All of the above

Question 2

Which of the following liquids contains the strongest acid?

Accepted Answer

A)   0.1 M HA, pH = 6.85
B)   0.1 M HD, pH = 7.22
C)   0.1 M HE, pH = 8.34
D)   0.1 M HJ, pH = 11.88
E)   pure waterF) A) and C)
G) All of the above

Question 3

The pH of a 0.200 M solution of the weak base pyridine, C5H5N, is 8.59.
A) Draw up a reaction table for the reaction of 0.200 M pyridine with water
B) Calculate Kb.

Accepted Answer

Question 4

Formic acid, HCOOH, is a weak acid with a pKa of 3.74.
A) Draw a reaction table for the reaction of 0.300 M formic acid with water.
B) Calculate the pH of this solution.

Accepted Answer

a. <img  loading="lazy" src="/assets/images/blured-textbook.svg" class="d-inline m-1" alt="blured image" width="139" height="30"> b. Assuming 0.30...

Question 5

Select the correct relationship among the concentrations of species present in a 1.0 M aqueous solution of the weak acid represented by HA.

Accepted Answer

A)   [H2O] > [A¯] ~ [H3O+] > [HA] > [OH¯]
B)   [H2O] > [HA] > [A¯] > [H3O+] > [OH¯]
C)   [HA] > [H2O] > [A¯] > [H3O+] > [OH¯]
D)   [H2O] > [HA] > [A¯] ~ [H3O+] > [OH¯]
E)   [HA] > [H2O] > [A¯] ~ [H3O+] > [OH¯]F) A) and D)
G) A) and C)

Question 6

According to Brønsted and Lowry, which one of the following is not a conjugate acid-base pair?

Accepted Answer

A)   H3O+, OH¯
B)   CH3OH2+, CH3OH
C)   HI, I¯
D)   HSO4¯, SO42¯
E)   H2, H¯F) C) and E)
G) B) and C)

Question 7

It is not possible to have a pH lying outside the range 0 to 14.

Accepted Answer

A) True 
 B)False

Question 8

Hydrated metal ions in aqueous solution can act as Brønsted-Lowry acids.

Accepted Answer

A) True 
 B)False

Question 9

Phosphoric acid, H3PO4, is a triprotic acid, for which Ka1 = 7.2 * 10¯3, Ka2 = 6.3 * 10¯8 and Ka3 = 4.2 * 10¯13. What is the value of Kb for the hydrogen phosphate anion, HPO42¯?

Accepted Answer

A)   6.3 * 10¯8
B)   4.2 * 10¯13
C)   1.4 * 10¯12
D)   1.6 * 10¯7
E)   2.4 * 10¯2F) A) and C)
G) A) and B)

Question 10

When 14.7 mL of aqueous HBr (a strong acid)  was added to water, 0.482 L of a solution with a pH of 4.23 was produced. What was the molarity of the original HBr solution?

Accepted Answer

A)   1.9 * 10¯3 M
B)   140 M
C)   0.288 M
D)   0.13 M
E)   None of these choices is correct.F) B) and D)
G) A) and C)

Question 11

What is the pH of a 0.00200 M HClO4 solution?

Accepted Answer

A)   0.995
B)   1.378
C)   2.699
D)   6.215
E)   None of these choices is correct.F) A) and B)
G) A) and C)

Question 12

A solution is prepared by adding 0.10 mol of sodium fluoride, NaF, to 1.00 L of water. Which statement about the solution is correct?

Accepted Answer

A)   The solution is basic.
B)   The solution is neutral.
C)   The solution is acidic.
D)   The concentrations of fluoride ions and sodium ions will be identical.
E)   The concentration of fluoride ions will be greater than the concentration of sodium ions.F) B) and C)
G) A) and E)

Question 13

A 0.050 M solution of the weak acid HA has [H3O+] = 3.77 * 10¯4 M. What is the Ka for the acid?

Accepted Answer

A)   7.5 * 10¯3 M
B)   2.8 *10¯6 M
C)   7.0 * 10¯7 M
D)   7.0 * 10¯8 M
E)   2.6 *10¯11 MF) A) and B)
G) A) and C)

Question 14

Which of the following is the strongest acid?

Accepted Answer

A)   CH3COOH
B)   HF
C)   H3PO4
D)   H2SO3
E)   HIF) A) and D)
G) A) and C)

Question 15

The strongest base which can exist in water is the hydroxide ion.

Accepted Answer

A) True 
 B)False

Question 16

What is the pH of a 0.050 M triethylamine, (C2H5) 3N, solution? Kb for triethylamine is 5.3 *10¯4.

Accepted Answer

A)   11.69
B)   8.68
C)   5.32
D)   2.31
E)   < 2.0F) A) and E)
G) B) and D)

Question 17

Arsenic acid, H3AsO4, is used industrially to manufacture insecticides. Arsenic acid is a polyprotic acid with K1 = 2.5 * 10¯4, K2 = 5.6 * 10¯8, and K3 = 3 *10¯13. What is the concentration of the HAsO42¯ in a solution whose initial arsenic acid concentration was 0.35 M ?

Accepted Answer

A)   9.4 *10¯3 M
B)   2.5 * 10¯4 M
C)   8.8 *10¯5 M
D)   5.6 * 10¯8 M
E)   None of these choices is correct.F) All of the above
G) A) and B)

Question 18

What is the pOH of a 0.0085 M KOH solution?

Accepted Answer

A)   2.07
B)   4.77
C)   9.23
D)   11.93
E)   None of these choices is correct.F) C) and D)
G) None of the above

Question 19

A solution is prepared by adding 0.10 mol of lithium nitrate, LiNO3, to 1.00 L of water. Which statement about the solution is correct?

Accepted Answer

A)   The solution is basic.
B)   The solution is neutral.
C)   The solution is weakly acidic.
D)   The solution is strongly acidic.
E)   The values for Ka and Kb for the species in solution must be known before a prediction can be made.F) C) and D)
G) B) and C)

Question 20

What is the pH of a 0.0035 M KOH solution?

Accepted Answer

A)   2.46
B)   5.65
C)   8.35
D)   11.54
E)   None of these choices is correct.F) A) and B)
G) A) and C)

Exam 18: Acid-Base Equilibria

Arsenic acid, H3AsO4, is used industrially to manufacture insecticides. Arsenic acid is a polyprotic acid with K1 = 2.5 * 10¯4, K2 = 5.6 * 10¯8, and K3 = 3 *10¯13. What is the concentration of the HAsO42¯ in a solution whose initial arsenic acid concentration was 0.35 M ?

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What is the pOH of a 0.0085 M KOH solution?

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Phosphoric acid, H3PO4, is a triprotic acid, for which Ka1 = 7.2 * 10¯3, Ka2 = 6.3 * 10¯8 and Ka3 = 4.2 * 10¯13. What is the value of Kb for the hydrogen phosphate anion, HPO42¯?

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What is the pH of a 0.050 M triethylamine, (C2H5) 3N, solution? Kb for triethylamine is 5.3 *10¯4.

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The strongest base which can exist in water is the hydroxide ion.

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A solution is prepared by adding 0.10 mol of lithium nitrate, LiNO3, to 1.00 L of water. Which statement about the solution is correct?

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When 14.7 mL of aqueous HBr (a strong acid) was added to water, 0.482 L of a solution with a pH of 4.23 was produced. What was the molarity of the original HBr solution?

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The pH of a 0.200 M solution of the weak base pyridine, C5H5N, is 8.59. A) Draw up a reaction table for the reaction of 0.200 M pyridine with water B) Calculate Kb.

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What is the pH of a 0.0035 M KOH solution?

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Formic acid, HCOOH, is a weak acid with a pKa of 3.74. A) Draw a reaction table for the reaction of 0.300 M formic acid with water. B) Calculate the pH of this solution.

Correct Answerverifieda. b. Assuming 0.30...View AnswerShow Answer

Which of the following is the strongest acid?

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Select the correct relationship among the concentrations of species present in a 1.0 M aqueous solution of the weak acid represented by HA.

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Which of the following liquids contains the strongest acid?

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What is the pH of a 0.00200 M HClO4 solution?

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The acid dissociation constant Ka equals 1.26 *10¯2 for HSO4¯ and is 5.6 *10¯10 for NH4+. Which statement about the following equilibrium is correct?

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According to Brønsted and Lowry, which one of the following is not a conjugate acid-base pair?

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A solution is prepared by adding 0.10 mol of sodium fluoride, NaF, to 1.00 L of water. Which statement about the solution is correct?

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It is not possible to have a pH lying outside the range 0 to 14.

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A 0.050 M solution of the weak acid HA has [H3O+] = 3.77 * 10¯4 M. What is the Ka for the acid?

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Hydrated metal ions in aqueous solution can act as Brønsted-Lowry acids.

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Arsenic acid, H₃AsO₄, is used industrially to manufacture insecticides. Arsenic acid is a polyprotic acid with K₁ = 2.5 * 10¯⁴, K₂ = 5.6 * 10¯⁸, and K₃ = 3 *10¯¹³. What is the concentration of the HAsO₄²¯ in a solution whose initial arsenic acid concentration was 0.35 M ?

Correct Answer
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Correct Answer
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Phosphoric acid, H₃PO₄, is a triprotic acid, for which K_a1 = 7.2 * 10¯³, K_a2 = 6.3 * 10¯⁸ and K_a3 = 4.2 * 10¯¹³. What is the value of K_b for the hydrogen phosphate anion, HPO₄²¯?

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What is the pH of a 0.050 M triethylamine, (C₂H₅) ₃N, solution? K_b for triethylamine is 5.3 *10¯⁴.

Correct Answer
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Correct Answer
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A solution is prepared by adding 0.10 mol of lithium nitrate, LiNO₃, to 1.00 L of water. Which statement about the solution is correct?

Correct Answer
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Correct Answer
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The pH of a 0.200 M solution of the weak base pyridine, C₅H₅N, is 8.59. A) Draw up a reaction table for the reaction of 0.200 M pyridine with water B) Calculate K_b.

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Correct Answer
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Formic acid, HCOOH, is a weak acid with a pK_a of 3.74. A) Draw a reaction table for the reaction of 0.300 M formic acid with water. B) Calculate the pH of this solution.

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a. b. Assuming 0.30...
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What is the pH of a 0.00200 M HClO₄ solution?

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The acid dissociation constant K_a equals 1.26 10¯² for HSO₄¯ and is 5.6 10¯¹⁰ for NH₄⁺. Which statement about the following equilibrium is correct?

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A 0.050 M solution of the weak acid HA has [H₃O⁺] = 3.77 * 10¯⁴ M. What is the K_a for the acid?

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Correct Answer
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