Question 1

Calculate the pH of 0.203 M HNO3(aq).

Accepted Answer

A) 0.693 
B) 2.030 
C) -1.140 
D) 13.797 
E) 1.595 
A) 0.693 
B) 2.030 
C) -1.140 
D) 13.797 
E) 1.595

Question 2

A monoprotic weak acid when dissolved in water is 0.75% dissociated and produces a solution with a pH of 3.11.Calculate the Ka of the acid.

Accepted Answer

A) 7.6 $\times$ 10-3 
B) 1.0 $\times$10-1 
C) 5.9 $\times$ 10-6 
D) Need to know the initial concentration of the acid. 
E) None of these. 
A) 7.6 $\times$ 10-3 
B) 1.0 $\times$10-1 
C) 5.9 $\times$ 10-6 
D) Need to know the initial concentration of the acid. 
E) None of these.

Question 3

Which of the following species cannot act as a Lewis base?

Accepted Answer

A) O2- 
B) OH- 
C) CH4 
D) H2S 
E) NH3 
A) O2- 
B) OH- 
C) CH4 
D) H2S 
E) NH3

Question 4

Which of the following species cannot act as a Lewis acid?

Accepted Answer

A) NH4+ 
B) H+ 
C) BF3 
D) BeCl2 
E) Ag+ 
A) NH4+ 
B) H+ 
C) BF3 
D) BeCl2 
E) Ag+

Question 5

The pH of a 1.0 M aqueous solution of NaCl is:

Accepted Answer

A) 7.0 
B) greater than 7.0 
C) less than 7.0 
D) not enough information given 
E) none of these (A-
D)  
A) 7.0 
B) greater than 7.0 
C) less than 7.0 
D) not enough information given 
E) none of these (A-
D)

Question 6

Which of the following is true about the pH of a solution of sulfuric acid?

Accepted Answer

A) If the solution is dilute the pH can not be calculated. 
B) If the solution is dilute the pH is completely controlled by the first dissociation. 
C) If the solution is dilute the pH is completely controlled by the second dissociation. 
D) If the solution is concentrated the pH is partially controlled by the second dissociation. 
E) If the solution is dilute the pH is partially controlled by the second dissociation. 
A) If the solution is dilute the pH can not be calculated. 
B) If the solution is dilute the pH is completely controlled by the first dissociation. 
C) If the solution is dilute the pH is completely controlled by the second dissociation. 
D) If the solution is concentrated the pH is partially controlled by the second dissociation. 
E) If the solution is dilute the pH is partially controlled by the second dissociation.

Question 7

True or false: The species Cl- is not a good base in aqueous solution.

Accepted Answer

A) True.This is because Cl- is the conjugate base of a weak acid. 
B) False.The species Cl- is a good base in aqueous solution because it is the conjugate base of a strong acid. 
C) True.This is because Cl- is a good proton donor. 
D) False.The species Cl- is a good base in aqueous solution because of its high electronegativity. 
E) True.This is because water has a stronger attraction for protons than does Cl-. 
A) True.This is because Cl- is the conjugate base of a weak acid. 
B) False.The species Cl- is a good base in aqueous solution because it is the conjugate base of a strong acid. 
C) True.This is because Cl- is a good proton donor. 
D) False.The species Cl- is a good base in aqueous solution because of its high electronegativity. 
E) True.This is because water has a stronger attraction for protons than does Cl-.

Question 8

The [OH-] in a 0.87 M pyridine (C5H5N;Kb = 1.7 $\times$ 10-9)solution is

Accepted Answer

A) 1.5 $\times$ 10-9 M 
B) 3.8 $\times$ 10-5 M 
C) 0.87 M 
D) 4.4 $\times$10-5 M 
E) none of these 
A) 1.5 $\times$ 10-9 M 
B) 3.8 $\times$ 10-5 M 
C) 0.87 M 
D) 4.4 $\times$10-5 M 
E) none of these

Question 9

What is the pOH of pure water at 65oC? (Kw at 65oC = 1.20 $\times$ 10-13)

Accepted Answer

A) 7.540 
B) 7.000 
C) 14.000 
D) 12.921 
E) 6.460 
A) 7.540 
B) 7.000 
C) 14.000 
D) 12.921 
E) 6.460

Question 10

For which of the following 0.10 M diprotic acids would the second dissociation affect the pH significantly?

Accepted Answer

A) H2A;Ka1 = 4.2 $\times$ 10-2,Ka2 = 1.8 $\times$ 10-7 
B) H2B;Ka1 = 2.4 $\times$10-4,Ka2 = 6.1 $\times$ 10-8 
C) H2C;Ka1 = 1.3 $\times$ 10-4,Ka2 = 5.2 $\times$ 10-9 
D) H2D;Ka1 = 1.8 $\times$ 10-3,Ka2 = 9.3$\times$ 10-4 
E) The second dissociation never affects the pH significantly. 
A) H2A;Ka1 = 4.2 $\times$ 10-2,Ka2 = 1.8 $\times$ 10-7 
B) H2B;Ka1 = 2.4 $\times$10-4,Ka2 = 6.1 $\times$ 10-8 
C) H2C;Ka1 = 1.3 $\times$ 10-4,Ka2 = 5.2 $\times$ 10-9 
D) H2D;Ka1 = 1.8 $\times$ 10-3,Ka2 = 9.3$\times$ 10-4 
E) The second dissociation never affects the pH significantly.

Question 11

A 8.5 $\times$ 10-3 M solution of a weak acid is 4.6% dissociated at 25°C.In a 8.5 $\times$ 10-4 M solution,the percentage of dissociation would be

Accepted Answer

A) the same 
B) > 4.6% 
C) a of the acid to answer this 
A) the same 
B) > 4.6% 
C) a of the acid to answer this

Question 12

For the equilibrium that exists in an aqueous solution of nitrous acid (HNO2,a weak acid),the equilibrium constant expression is:

Accepted Answer

A) K =   
B) K =   
C) K = [H+][NO2-] 
D) K =   
E) none of these 
A) K =   
B) K =   
C) K = [H+][NO2-] 
D) K =   
E) none of these

Question 13

Explain why 0.1 M NaCN is basic while 0.1 M NaNO3 is neutral.

Accepted Answer

When NaCN dissolves in water,it produces

Question 14

Calculate the pH of a 0.059 M solution of Ca(OH)2.

Accepted Answer

A) 13.07 
B) 12.77 
C) 0.93 
D) 1.23 
E) none of these 
A) 13.07 
B) 12.77 
C) 0.93 
D) 1.23 
E) none of these

Question 15

The salt BX,when dissolved in water,produces an acidic solution.Which of the following could be true?

Accepted Answer

A) HX is a weak acid. 
B) HX is a strong acid. 
C) The cation B+ is a weak acid. 
D) All of the above could be true. 
E) Only A and C could be true. 
A) HX is a weak acid. 
B) HX is a strong acid. 
C) The cation B+ is a weak acid. 
D) All of the above could be true. 
E) Only A and C could be true.

Question 16

Determine whether the following oxides produce an acidic,basic,or neutral solution when dissolved in water:
-K2O

Accepted Answer

basic K₂O

Question 17

A 0.372-g sample of NaOH(s)is added to enough water to make 250.0 mL of solution.The pH of this solution is:

Accepted Answer

A) 1.429 
B) 0.429 
C) 11.968 
D) 12.571 
E) none of these 
A) 1.429 
B) 0.429 
C) 11.968 
D) 12.571 
E) none of these

Question 18

In a solution prepared by dissolving 0.100 mole of propanoic acid in enough water to make 1.00 L of solution,the pH is observed to be 2.832.The Ka for propanoic acid (HC3H5O2)is:

Accepted Answer

A) 1.47 $\times$ 10-3 
B) 2.20 $\times$10-5 
C) 1.49 $\times$10-2 
D) 4.55 $\times$ 10-10 
E) none of these 
A) 1.47 $\times$ 10-3 
B) 2.20 $\times$10-5 
C) 1.49 $\times$10-2 
D) 4.55 $\times$ 10-10 
E) none of these

Question 19

Determine the pH of a 0.034 M solution of H2SO4.The dissociation occurs in two steps.Ka1 is extremely large;Ka2 is 1.2 $\times$ 10-2.

Accepted Answer

A) 12.66 
B) 1.47 
C) 1.92 
D) 1.38 
E) 2.12 
A) 12.66 
B) 1.47 
C) 1.92 
D) 1.38 
E) 2.12

Question 20

Which of the following is the strongest base? (Kb for NH3 is 1.8 $\times$ 10-5,Ka2 for H2SO4 is 1.2 $\times$ 10-2,Ka3 for H3PO4 is 4.8 $\times$ 10-13) NH3,HSO4-,PO43-,or NO3-

Accepted Answer

A) NH3 
B) HSO4- 
C) NO3- 
D) PO43- 
E) Two of these are equally strong. 
A) NH3 
B) HSO4- 
C) NO3- 
D) PO43- 
E) Two of these are equally strong.

Exam 14: Acids and Bases

Calculate the pH of 0.203 M HNO3(aq).

A monoprotic weak acid when dissolved in water is 0.75% dissociated and produces a solution with a pH of 3.11.Calculate the Ka of the acid.

Which of the following species cannot act as a Lewis base?

Which of the following species cannot act as a Lewis acid?

The pH of a 1.0 M aqueous solution of NaCl is:

Which of the following is true about the pH of a solution of sulfuric acid?

True or false: The species Cl- is not a good base in aqueous solution.

The [OH-] in a 0.87 M pyridine (C5H5N;Kb = 1.7 ×\times× 10-9)solution is

What is the pOH of pure water at 65oC? (Kw at 65oC = 1.20 ×\times× 10-13)

For which of the following 0.10 M diprotic acids would the second dissociation affect the pH significantly?

A 8.5 ×\times× 10-3 M solution of a weak acid is 4.6% dissociated at 25°C.In a 8.5 ×\times× 10-4 M solution,the percentage of dissociation would be

For the equilibrium that exists in an aqueous solution of nitrous acid (HNO2,a weak acid),the equilibrium constant expression is:

Explain why 0.1 M NaCN is basic while 0.1 M NaNO3 is neutral.

Calculate the pH of a 0.059 M solution of Ca(OH)2.

The salt BX,when dissolved in water,produces an acidic solution.Which of the following could be true?

Determine whether the following oxides produce an acidic,basic,or neutral solution when dissolved in water: -K2O

A 0.372-g sample of NaOH(s)is added to enough water to make 250.0 mL of solution.The pH of this solution is:

In a solution prepared by dissolving 0.100 mole of propanoic acid in enough water to make 1.00 L of solution,the pH is observed to be 2.832.The Ka for propanoic acid (HC3H5O2)is:

Determine the pH of a 0.034 M solution of H2SO4.The dissociation occurs in two steps.Ka1 is extremely large;Ka2 is 1.2 ×\times× 10-2.

Which of the following is the strongest base? (Kb for NH3 is 1.8 ×\times× 10-5,Ka2 for H2SO4 is 1.2 ×\times× 10-2,Ka3 for H3PO4 is 4.8 ×\times× 10-13) NH3,HSO4-,PO43-,or NO3-

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Filters

Calculate the pH of 0.203 M HNO₃(aq).

A monoprotic weak acid when dissolved in water is 0.75% dissociated and produces a solution with a pH of 3.11.Calculate the K_a of the acid.

True or false: The species Cl^- is not a good base in aqueous solution.

The [OH^-] in a 0.87 M pyridine (C₅H₅N;K_b = 1.7 $\times$ 10^-⁹)solution is

What is the pOH of pure water at 65^oC? (K_w at 65^oC = 1.20 $\times$ 10^-¹³)

A 8.5 $\times$ 10^-³ M solution of a weak acid is 4.6% dissociated at 25°C.In a 8.5 $\times$ 10^-⁴ M solution,the percentage of dissociation would be

For the equilibrium that exists in an aqueous solution of nitrous acid (HNO₂,a weak acid),the equilibrium constant expression is:

Explain why 0.1 M NaCN is basic while 0.1 M NaNO₃ is neutral.

Calculate the pH of a 0.059 M solution of Ca(OH)₂.

Determine whether the following oxides produce an acidic,basic,or neutral solution when dissolved in water: -K₂O

In a solution prepared by dissolving 0.100 mole of propanoic acid in enough water to make 1.00 L of solution,the pH is observed to be 2.832.The K_a for propanoic acid (HC₃H₅O₂)is:

Determine the pH of a 0.034 M solution of H₂SO₄.The dissociation occurs in two steps.K_a1 is extremely large;K_a2 is 1.2 $\times$ 10^-².

Which of the following is the strongest base? (K_b for NH₃ is 1.8 $\times$ 10^-⁵,K_a2for H₂SO₄ is 1.2 $\times$ 10^-²,K_a3 for H₃PO₄ is 4.8 $\times$ 10^-¹³) NH₃,HSO₄^-,PO₄³^-,or NO₃^-