Question 1

Ammonia is a ________.

Accepted Answer

A) weak acid 
B) strong base 
C) weak base 
D) strong acid 
E) salt 
A) weak acid 
B) strong base 
C) weak base 
D) strong acid 
E) salt

Question 2

The conjugate base of H2PO4- is ________.

Accepted Answer

A) PO43- 
B) H2PO4 
C) H3PO4 
D) HPO42- 
E) none of the above 
A) PO43- 
B) H2PO4 
C) H3PO4 
D) HPO42- 
E) none of the above

Question 3

What is the pH of a sodium formate (NaCHO2)solution prepared by adding 0.680 grams of sodium formate to 100.0 ml of water at 25.0 °C? The Ka at 25.0 °C for formic acid is 1.8 × 10-4.

Accepted Answer

Question 4

Of the following, which is the weakest acid?

Accepted Answer

A) HPO3- 
B) H3PO4 
C) H2PO4- 
D) HPO4- 
E) The acid strength of all of the above is the same. 
A) HPO3- 
B) H3PO4 
C) H2PO4- 
D) HPO4- 
E) The acid strength of all of the above is the same.

Question 5

An aqueous solution contains 0.050 M of methylamine. The concentration of hydroxide ion in this solution is ________ M. Kb for methylamine is 4.4 × 10-4.

Accepted Answer

A) 0.050 
B) 2.2 × 10-5 
C) 2.9 × 10-3 
D) 4.5 × 10-3 
E) 4.7 × 10-3 
A) 0.050 
B) 2.2 × 10-5 
C) 2.9 × 10-3 
D) 4.5 × 10-3 
E) 4.7 × 10-3

Question 6

What is the pOH of an aqueous solution at 25.0 °C in which [H+] is 0.0050 M?

Accepted Answer

A) 8.70 
B) 11.70 
C) -11.70 
D) -8.70 
E) none of the above 
A) 8.70 
B) 11.70 
C) -11.70 
D) -8.70 
E) none of the above

Question 7

Calculate the pH of a 0.0727 M aqueous sodium cyanide solution at 25.0 °C. Kb for CN- is 4.9 × 10-10.

Accepted Answer

A) 9.33 
B) 10.00 
C) 5.22 
D) 1.14 
E) 8.78 
A) 9.33 
B) 10.00 
C) 5.22 
D) 1.14 
E) 8.78

Question 8

Calculate the pOH of a solution at 25.0 °C that contains 1.94 × 10-10 M hydronium ions.

Accepted Answer

A) 1.94 
B) 4.29 
C) 7.00 
D) 14.0 
E) 9.71 
A) 1.94 
B) 4.29 
C) 7.00 
D) 14.0 
E) 9.71

Question 9

The conjugate acid of HSO4- is ________.

Accepted Answer

A) SO42- 
B) H2SO4 
C) HSO4+ 
D) H+ 
E) HSO3+ 
A) SO42- 
B) H2SO4 
C) HSO4+ 
D) H+ 
E) HSO3+

Question 10

Calculate the pOH of 0.606 M anilinium hydrochloride (C6H5NH3Cl)solution in water, given that Kb for aniline is 3.83 × 10-4.

Accepted Answer

A) 1.82 
B) 12.18 
C) 5.40 
D) 8.60 
E) 12.42 
A) 1.82 
B) 12.18 
C) 5.40 
D) 8.60 
E) 12.42

Question 11

Of the acids in the table below, ________ is the strongest acid.

Accepted Answer

A) HOAc 
B) HCHO2 
C) HClO 
D) HF 
E) HOAc and HCHO2 
A) HOAc 
B) HCHO2 
C) HClO 
D) HF 
E) HOAc and HCHO2

Question 12

An aqueous solution contains 0.150 M HCl at 25.0 °C. The pH of the solution is ________.

Accepted Answer

A) 0.150 
B) 1.00 
C) 13.00 
D) 7.00 
E) 0.82 
A) 0.150 
B) 1.00 
C) 13.00 
D) 7.00 
E) 0.82

Question 13

Hydrochloric acid is a strong acid. This means that ________.

Accepted Answer

A) HCl dissociates completely to H+(aq)and Cl-(aq)when it dissolves in water 
B) HCl does not dissociate at all when it is dissolved in water 
C) HCl produces a gaseous product when it is neutralized 
D) HCl cannot be neutralized by a weak base 
E) aqueous solutions of HCl contain equal concentrations of H+(aq)and OH-(aq) 
A) HCl dissociates completely to H+(aq)and Cl-(aq)when it dissolves in water 
B) HCl does not dissociate at all when it is dissolved in water 
C) HCl produces a gaseous product when it is neutralized 
D) HCl cannot be neutralized by a weak base 
E) aqueous solutions of HCl contain equal concentrations of H+(aq)and OH-(aq)

Question 14

The conjugate base of NH3 is ________.

Accepted Answer

A) NH2- 
B) NH4+ 
C) NH2OH 
D) H3O+ 
E) OH- 
A) NH2- 
B) NH4+ 
C) NH2OH 
D) H3O+ 
E) OH-

Question 15

Which of the following aqueous solutions has the highest [OH-]?

Accepted Answer

A) a solution with a pH of 3.0 
B) a 1 × 10-4 M solution of HNO3 
C) a solution with a pOH of 12.0 
D) pure water 
E) a 1 × 10-3 M solution of NH4Cl 
A) a solution with a pH of 3.0 
B) a 1 × 10-4 M solution of HNO3 
C) a solution with a pOH of 12.0 
D) pure water 
E) a 1 × 10-3 M solution of NH4Cl

Question 16

The acid-dissociation constants of phosphoric acid (H3PO4)are Ka1 = 7.5 × 10-3, Ka2 = 6.2 × 10-8, and Ka3 = 4.2 × 10-13 at 25.0 °C. What is the pH of a 2.5 M aqueous solution of phosphoric acid?

Accepted Answer

A) 1.82 
B) 0.40 
C) 2.51 
D) 0.86 
E) 0.13 
A) 1.82 
B) 0.40 
C) 2.51 
D) 0.86 
E) 0.13

Question 17

The Ka for HCN is 4.9 × 10-10. What is the value of Kb for CN-?

Accepted Answer

A) 2.0 × 10-5 
B) 4.0 × 10-6 
C) 4.9 × 104 
D) 4.9 × 10-24 
E) 2.0 × 109 
A) 2.0 × 10-5 
B) 4.0 × 10-6 
C) 4.9 × 104 
D) 4.9 × 10-24 
E) 2.0 × 109

Question 18

What is the pOH of an aqueous solution at 25.0 °C in which [OH-] is 0.0010 M?

Accepted Answer

A) 11.00 
B) -3.00 
C) 3.00 
D) -11.00 
E) 6.91 
A) 11.00 
B) -3.00 
C) 3.00 
D) -11.00 
E) 6.91

Question 19

Which one of the following statements regarding Kw is false?

Accepted Answer

A) pKw is 14.00 at 25 °C. 
B) The value of Kw is always 1.0 × 10-14. 
C) Kw changes with temperature. 
D) The value of Kw shows that water is a weak acid. 
E) Kw is known as the ion product of water. 
A) pKw is 14.00 at 25 °C. 
B) The value of Kw is always 1.0 × 10-14. 
C) Kw changes with temperature. 
D) The value of Kw shows that water is a weak acid. 
E) Kw is known as the ion product of water.

Exam 16: Acid-Base Equilibria

Ammonia is a ________.

The conjugate base of H2PO4- is ________.

What is the pH of a sodium formate (NaCHO2)solution prepared by adding 0.680 grams of sodium formate to 100.0 ml of water at 25.0 °C? The Ka at 25.0 °C for formic acid is 1.8 × 10-4.

Of the following, which is the weakest acid?

An aqueous solution contains 0.050 M of methylamine. The concentration of hydroxide ion in this solution is ________ M. Kb for methylamine is 4.4 × 10-4.

What is the pOH of an aqueous solution at 25.0 °C in which [H+] is 0.0050 M?

Calculate the pH of a 0.0727 M aqueous sodium cyanide solution at 25.0 °C. Kb for CN- is 4.9 × 10-10.

Calculate the pOH of a solution at 25.0 °C that contains 1.94 × 10-10 M hydronium ions.

The conjugate acid of HSO4- is ________.

Calculate the pOH of 0.606 M anilinium hydrochloride (C6H5NH3Cl)solution in water, given that Kb for aniline is 3.83 × 10-4.

Of the acids in the table below, ________ is the strongest acid.

An aqueous solution contains 0.150 M HCl at 25.0 °C. The pH of the solution is ________.

Hydrochloric acid is a strong acid. This means that ________.

The conjugate base of NH3 is ________.

Which of the following aqueous solutions has the highest [OH-]?

The acid-dissociation constants of phosphoric acid (H3PO4)are Ka1 = 7.5 × 10-3, Ka2 = 6.2 × 10-8, and Ka3 = 4.2 × 10-13 at 25.0 °C. What is the pH of a 2.5 M aqueous solution of phosphoric acid?

The Ka for HCN is 4.9 × 10-10. What is the value of Kb for CN-?

What is the pOH of an aqueous solution at 25.0 °C in which [OH-] is 0.0010 M?

Which one of the following statements regarding Kw is false?

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Filters

The conjugate base of H₂PO₄^- is ________.

What is the pH of a sodium formate (NaCHO₂)solution prepared by adding 0.680 grams of sodium formate to 100.0 ml of water at 25.0 °C? The K_a at 25.0 °C for formic acid is 1.8 × 10^-4.

An aqueous solution contains 0.050 M of methylamine. The concentration of hydroxide ion in this solution is ________ M. K_b for methylamine is 4.4 × 10^-4.

What is the pOH of an aqueous solution at 25.0 °C in which [H⁺] is 0.0050 M?

Calculate the pH of a 0.0727 M aqueous sodium cyanide solution at 25.0 °C. K_b for CN^- is 4.9 × 10^-¹⁰.

Calculate the pOH of a solution at 25.0 °C that contains 1.94 × 10^-10 M hydronium ions.

The conjugate acid of HSO₄^- is ________.

Calculate the pOH of 0.606 M anilinium hydrochloride (C₆H₅NH₃Cl)solution in water, given that K_b for aniline is 3.83 × 10^-4.

The conjugate base of NH₃ is ________.

Which of the following aqueous solutions has the highest [OH^-]?

The acid-dissociation constants of phosphoric acid (H₃PO₄)are K_a1 = 7.5 × 10^-3, K_a2= 6.2 × 10^-⁸, and K_a3 = 4.2 × 10^-13 at 25.0 °C. What is the pH of a 2.5 M aqueous solution of phosphoric acid?

The K_a for HCN is 4.9 × 10^-10. What is the value of K_b for CN^-?

What is the pOH of an aqueous solution at 25.0 °C in which [OH^-] is 0.0010 M?

Which one of the following statements regarding K_w is false?