Question 1

What is the pH of an aqueous solution at 25.0 °C that contains 3.98 × 10-9 M hydronium ion?

Accepted Answer

A) 8.400 
B) 5.600 
C) 9.000 
D) 3.980 
E) 7.000 
A) 8.400 
B) 5.600 
C) 9.000 
D) 3.980 
E) 7.000

Question 2

Calculate the molarity of hydroxide ion in an aqueous solution that has a pOH of 3.00.

Accepted Answer

A) 1.0 × 10-3 
B) 11.00 
C) 1.0 × 10-11 
D) 3.0 × 10-14 
E) 1.1 × 10-13 
A) 1.0 × 10-3 
B) 11.00 
C) 1.0 × 10-11 
D) 3.0 × 10-14 
E) 1.1 × 10-13

Question 3

The Ka of acetic acid (HC2H3O2)is 1.8 × 10-5. What is the pH at 25.0 °C of an aqueous solution that is 0.100 M in acetic acid?

Accepted Answer

A) +2.87 
B) -2.87 
C) -11.13 
D) +11.13 
E) +6.61 
A) +2.87 
B) -2.87 
C) -11.13 
D) +11.13 
E) +6.61

Question 4

Determine the pH of a 0.35 M aqueous solution of CH3NH2 (methylamine). The Kb of methylamine is 4.4 × 10-4.

Accepted Answer

A) 10.00 
B) 3.86 
C) 12.09 
D) 1.96 
E) 13.24 
A) 10.00 
B) 3.86 
C) 12.09 
D) 1.96 
E) 13.24

Question 5

What is the pOH of a 0.030 M solution of barium hydroxide?

Accepted Answer

A) 12.78 
B) 12.48 
C) 1.52 
D) 1.22 
E) 10.41 
A) 12.78 
B) 12.48 
C) 1.52 
D) 1.22 
E) 10.41

Question 6

Using the data in the table, which of the conjugate acids below is the strongest acid?

Accepted Answer

A) NH4+ 
B) C5H5NH+ 
C) H3NOH+ 
D) NH3CH3+ 
E) NH4+ and NH3CH3+ 
A) NH4+ 
B) C5H5NH+ 
C) H3NOH+ 
D) NH3CH3+ 
E) NH4+ and NH3CH3+

Question 7

What is the pH of an aqueous solution at 25.0 °C in which [H+] is 0.0015 M?

Accepted Answer

A) 6.50 
B) 2.82 
C) -2.82 
D) -6.50 
E) none of the above 
A) 6.50 
B) 2.82 
C) -2.82 
D) -6.50 
E) none of the above

Question 8

A solution of ammonia is 2.0% ionized at 25.0 °C. What was the original concentration (in M)of the ammonia solution? The Kb at 25.0 °C for ammonia is 1.8 × 10-5.

Accepted Answer

Question 9

The Ka of hydrofluoric acid (HF)at 25.0 °C is 6.8 × 10-4. What is the pH of a 0.45 M aqueous solution of HF?

Accepted Answer

A) 4.05 
B) 1.76 
C) 3.64 
D) 0.35 
E) 1.41 
A) 4.05 
B) 1.76 
C) 3.64 
D) 0.35 
E) 1.41

Question 10

The pH of a 0.60 M aqueous solution of formic acid, HCHO2, at 25.0 °C is 1.98. What is the value of Ka for formic acid?

Accepted Answer

A) 2.0 × 10-5 
B) 1.8 × 10-4 
C) 6.0 × 10-5 
D) 3.5 × 10-4 
E) none of the above 
A) 2.0 × 10-5 
B) 1.8 × 10-4 
C) 6.0 × 10-5 
D) 3.5 × 10-4 
E) none of the above

Question 11

The molar concentration of hydronium ion in pure water at 25 °C is ________.

Accepted Answer

A) 0.00 
B) 1.0 × 10-7 
C) 1.0 × 10-14 
D) 1.00 
E) 7.00 
A) 0.00 
B) 1.0 × 10-7 
C) 1.0 × 10-14 
D) 1.00 
E) 7.00

Question 12

An aqueous solution of ________ will produce an acidic solution.

Accepted Answer

A) NH4I 
B) KBr 
C) Sr(ClO4)2 
D) K2CO3 
E) NaNO3 
A) NH4I 
B) KBr 
C) Sr(ClO4)2 
D) K2CO3 
E) NaNO3

Question 13

What is the pOH of an aqueous solution at 25.0 °C that contains 3.98 × 10-9 M hydroxide ion?

Accepted Answer

A) 8.40 
B) 5.60 
C) 9.00 
D) 3.98 
E) 7.00 
A) 8.40 
B) 5.60 
C) 9.00 
D) 3.98 
E) 7.00

Question 14

Of the compounds below, a 0.1 M aqueous solution of ________ will have the highest pH.

Accepted Answer

A) KCN, Ka of HCN = 4.0 × 10-10 
B) NH4NO3, Kb of NH3 = 1.8 × 10-5 
C) NaOAc, Ka of HOAc = 1.8 × 10-5 
D) NaClO, Ka of HClO = 3.2 × 10-8 
E) NaHS, Kb of HS- = 1.8 × 10-7 
A) KCN, Ka of HCN = 4.0 × 10-10 
B) NH4NO3, Kb of NH3 = 1.8 × 10-5 
C) NaOAc, Ka of HOAc = 1.8 × 10-5 
D) NaClO, Ka of HClO = 3.2 × 10-8 
E) NaHS, Kb of HS- = 1.8 × 10-7

Question 15

An aqueous solution contains 0.100 M NaOH at 25.0 °C. The pH of the solution is ________.

Accepted Answer

A) 0.100 
B) 1.00 
C) 13.00 
D) 7.00 
E) -1.00 
A) 0.100 
B) 1.00 
C) 13.00 
D) 7.00 
E) -1.00

Question 16

The Ka of hydrazoic acid (HN3)is 1.9 × 10-5 at 25.0 °C. What is the pH of a 0.15 M aqueous solution of HN3?

Accepted Answer

A) 0.82 
B) 1.95 
C) 5.23 
D) 2.77 
E) -3.46 
A) 0.82 
B) 1.95 
C) 5.23 
D) 2.77 
E) -3.46

Question 17

What is the conjugate base of OH-?

Accepted Answer

A) O2 
B) O- 
C) H2O 
D) O2- 
E) H3O+ 
A) O2 
B) O- 
C) H2O 
D) O2- 
E) H3O+

Question 18

Calculate the pH of a 0.500 M aqueous solution of NH3. The Kb of NH3 is 1.77 × 10-5.

Accepted Answer

A) 8.95 
B) 11.47 
C) 2.53 
D) 11.77 
E) 2.23 
A) 8.95 
B) 11.47 
C) 2.53 
D) 11.77 
E) 2.23

Question 19

Which of the following ions will act as a weak base in water?

Accepted Answer

A) HS- 
B) F- 
C) NO2- 
D) ClO- 
E) All of the above will act as a weak base in water. 
A) HS- 
B) F- 
C) NO2- 
D) ClO- 
E) All of the above will act as a weak base in water.

Question 20

What is the pH of a sodium acetate (NaC2H3O2)solution prepared by adding 0.820 grams of sodium acetate to 100.0 ml of water at 25.0 °C? The Ka at 25.0 °C for acetic acid is 1.8 × 10-5.

Accepted Answer

Exam 16: Acid-Base Equilibria

What is the pH of an aqueous solution at 25.0 °C that contains 3.98 × 10-9 M hydronium ion?

Calculate the molarity of hydroxide ion in an aqueous solution that has a pOH of 3.00.

The Ka of acetic acid (HC2H3O2)is 1.8 × 10-5. What is the pH at 25.0 °C of an aqueous solution that is 0.100 M in acetic acid?

Determine the pH of a 0.35 M aqueous solution of CH3NH2 (methylamine). The Kb of methylamine is 4.4 × 10-4.

What is the pOH of a 0.030 M solution of barium hydroxide?

Using the data in the table, which of the conjugate acids below is the strongest acid?

What is the pH of an aqueous solution at 25.0 °C in which [H+] is 0.0015 M?

A solution of ammonia is 2.0% ionized at 25.0 °C. What was the original concentration (in M)of the ammonia solution? The Kb at 25.0 °C for ammonia is 1.8 × 10-5.

The Ka of hydrofluoric acid (HF)at 25.0 °C is 6.8 × 10-4. What is the pH of a 0.45 M aqueous solution of HF?

The pH of a 0.60 M aqueous solution of formic acid, HCHO2, at 25.0 °C is 1.98. What is the value of Ka for formic acid?

The molar concentration of hydronium ion in pure water at 25 °C is ________.

An aqueous solution of ________ will produce an acidic solution.

What is the pOH of an aqueous solution at 25.0 °C that contains 3.98 × 10-9 M hydroxide ion?

Of the compounds below, a 0.1 M aqueous solution of ________ will have the highest pH.

An aqueous solution contains 0.100 M NaOH at 25.0 °C. The pH of the solution is ________.

The Ka of hydrazoic acid (HN3)is 1.9 × 10-5 at 25.0 °C. What is the pH of a 0.15 M aqueous solution of HN3?

What is the conjugate base of OH-?

Calculate the pH of a 0.500 M aqueous solution of NH3. The Kb of NH3 is 1.77 × 10-5.

Which of the following ions will act as a weak base in water?

What is the pH of a sodium acetate (NaC2H3O2)solution prepared by adding 0.820 grams of sodium acetate to 100.0 ml of water at 25.0 °C? The Ka at 25.0 °C for acetic acid is 1.8 × 10-5.

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Filters

What is the pH of an aqueous solution at 25.0 °C that contains 3.98 × 10^-9 M hydronium ion?

The K_a of acetic acid (HC₂H₃O₂)is 1.8 × 10^-5. What is the pH at 25.0 °C of an aqueous solution that is 0.100 M in acetic acid?

Determine the pH of a 0.35 M aqueous solution of CH₃NH₂ (methylamine). The K_b of methylamine is 4.4 × 10^-4.

What is the pH of an aqueous solution at 25.0 °C in which [H⁺] is 0.0015 M?

A solution of ammonia is 2.0% ionized at 25.0 °C. What was the original concentration (in M)of the ammonia solution? The K_b at 25.0 °C for ammonia is 1.8 × 10^-5.

The K_a of hydrofluoric acid (HF)at 25.0 °C is 6.8 × 10^-4. What is the pH of a 0.45 M aqueous solution of HF?

The pH of a 0.60 M aqueous solution of formic acid, HCHO₂, at 25.0 °C is 1.98. What is the value of K_a for formic acid?

What is the pOH of an aqueous solution at 25.0 °C that contains 3.98 × 10^-9 M hydroxide ion?

The K_a of hydrazoic acid (HN₃)is 1.9 × 10^-⁵ at 25.0 °C. What is the pH of a 0.15 M aqueous solution of HN₃?

What is the conjugate base of OH^-?

Calculate the pH of a 0.500 M aqueous solution of NH₃. The K_b of NH₃ is 1.77 × 10^-⁵.

What is the pH of a sodium acetate (NaC₂H₃O₂)solution prepared by adding 0.820 grams of sodium acetate to 100.0 ml of water at 25.0 °C? The K_a at 25.0 °C for acetic acid is 1.8 × 10^-5.