Question 1

What is the pH of a 1.0 M aqueous solution of trisodium phosphate? Ka1 = 7.1 × 10-3,Ka2 = 6.3 × 10-8,
Ka3 = 4.2 × 10-13

Accepted Answer

A) 1.6 
B) 7.0 
C) 12.4 
D) 6.2 
E) 7.8 
A) 1.6 
B) 7.0 
C) 12.4 
D) 6.2 
E) 7.8

Question 2

An aqueous solution of an unknown acid had a pH of 3.70.Titration of a 25.0 mL aliquot of the acid solution required 21.7 mL of 0.104 M aqueous sodium hydroxide for complete reaction.Assuming that the acid is monoprotic,what is its ionization constant?

Accepted Answer

A) 9.0 × 10-2  
B) 2.0 × 10-4  
C) 4.4 × 10-7  
D) 3.6 × 10-9  
E) 2.7 × 10-11  
A) 9.0 × 10-2  
B) 2.0 × 10-4  
C) 4.4 × 10-7  
D) 3.6 × 10-9  
E) 2.7 × 10-11

Question 3

What is the pH of the resulting solution if 25.00 mL of 0.10 mol L-1 aqueous acetic acid is added to 10.00 mL of 0.10 mol L-1 NaOH(aq)? 
Assume that the volumes of the solutions are additive.Ka = 1.8 × 10-5 for CH3COOH

Accepted Answer

A) 9.43 
B) 9.08 
C) 4.92 
D) 4.57 
A) 9.43 
B) 9.08 
C) 4.92 
D) 4.57

Question 4

A handbook states that to prepare a particular buffer solution mix 39.0 mL of 0.20 M aqueous NaH2PO4 with 61.0 mL of 0.20 M aqueous Na2HPO4.What will be the pH of this buffer? For phosphoric acid Ka2= 6.2 × 10-8

Accepted Answer

A) 7.2 
B) 7.4 
C) 7.0 
D) 6.8 
E) 6.6 
A) 7.2 
B) 7.4 
C) 7.0 
D) 6.8 
E) 6.6

Question 5

The common ion in an aqueous solution of a weak acid and a strong acid is the hydronium ion.

Accepted Answer

A) True 
 B)False

Question 6

Determine the [C2H3O2-] of the following aqueous solution.Initial concentrations are given.
[HC2H3O2] = 0.250 M,[HI] = 0.120 M Ka (acetic acid)= 1.8 × 10-5

Accepted Answer

A) 8.6 × 10-6 M 
B) 3.8 × 10-5 M 
C) 1.8 × 10-5 M 
D) 0.25 M 
E) 0.37 M 
A) 8.6 × 10-6 M 
B) 3.8 × 10-5 M 
C) 1.8 × 10-5 M 
D) 0.25 M 
E) 0.37 M

Question 7

How many millilitres of 0.120 mol L-1 NaOH(aq)are required to titrate 50.0 mL of 0.0998 mol L-1 aqueous butanoic acid to the equivalence point? Butanoic acid is monoprotic.The  
Of butanoic acid is 1.5 × 10-5.

Accepted Answer

A) 4.90 
B) 50.0 
C) 41.6 
D) 60.1 
E) 4.65 
A) 4.90 
B) 50.0 
C) 41.6 
D) 60.1 
E) 4.65

Question 8

A weak acid has Ka = 4.2 × 10-3.If [A-] = 2.0 M,what must [HA] be so that [H+] = 2.1 × 10-3 M?

Accepted Answer

A) 1.5 M 
B) 2.0 M 
C) 1.0 M 
D) 0.5 M 
E) 0.25 M 
A) 1.5 M 
B) 2.0 M 
C) 1.0 M 
D) 0.5 M 
E) 0.25 M

Question 9

The following compounds are available as 0.10 M aqueous solutions: pyridine (pKb = 8.82),triethylamine (pKb = 3.25),HClO4,phenol (pKa = 9.96),HClO (pKa = 7.54),NH3 (pKb = 4.74)and NaOH.Identify two solutions that could be used to prepare a buffer with a pH of approximately 5.

Accepted Answer

A) pyridine and HClO4 
B) triethylamine and HClO4 
C) phenol and NaOH 
D) HClO and NaOH 
E) HClO and NH3 
A) pyridine and HClO4 
B) triethylamine and HClO4 
C) phenol and NaOH 
D) HClO and NaOH 
E) HClO and NH3

Question 10

What is the pH of an aqueous solution prepared by mixing 50.00 mL of 0.10 mol L-1 methylamine,CH3NH2,with 20.00 mL of 0.10 mol L-1 methylammonium chloride,CH3NH3Cl? Assume that the volume of the solutions are additive and that Kb = 3.70 × 10-4 for methylamine.

Accepted Answer

A) 10.17 
B) 10.57 
C) 10.97 
D) 11.78 
A) 10.17 
B) 10.57 
C) 10.97 
D) 11.78

Question 11

What is the [H3O+] of an aqueous solution measured to be 0.20 M in sodium acetate and 0.40 M in acetic acid? (Ka = 1.8 × 10-5)

Accepted Answer

A) 1.8 × 10-5 M 
B) 9.0 × 10-6 M 
C) 3.6 × 10-5 M 
D) 7.2 × 10-5 M 
E) 4.7 M 
A) 1.8 × 10-5 M 
B) 9.0 × 10-6 M 
C) 3.6 × 10-5 M 
D) 7.2 × 10-5 M 
E) 4.7 M

Question 12

How many mL of 0.200 M aqueous acetic acid are mixed with 13.2 mL of 0.200 M aqueous sodium acetate to give a buffer with pH = 4.2? (Ka for acetic acid is 1.8 × 10-5)

Accepted Answer

A) 37 mL 
B) 18 mL 
C) 3.8 mL 
D) 14 mL 
E) 46 mL 
A) 37 mL 
B) 18 mL 
C) 3.8 mL 
D) 14 mL 
E) 46 mL

Question 13

What is the pH of a 1.0 M aqueous solution of Na2SO3? Ka1 = 1.3 × 10-2,Ka2 = 6.2 × 10-8?

Accepted Answer

A) 6.8 
B) 7.2 
C) 7.0 
D) 10.4 
E) 3.6 
A) 6.8 
B) 7.2 
C) 7.0 
D) 10.4 
E) 3.6

Question 14

Determine the pH of the following aqueous solution.Initial concentrations are given.
[NaCHO2] = 0.815 M,[HBr] = 0.105 M,Ka for HCHO2= 1.8 × 10-4

Accepted Answer

A) 2.91 
B) 4.63 
C) 4.57 
D) 9.43 
E) 11.09 
A) 2.91 
B) 4.63 
C) 4.57 
D) 9.43 
E) 11.09

Question 15

If some NH4Cl is added to an aqueous solution of NH3:

Accepted Answer

A) the pH of the solution will increase 
B) the pH of the solution will decrease 
C) the solution will not have pH 
D) the pH of the solution will not change 
E) NH4Cl cannot be added to NH3  
A) the pH of the solution will increase 
B) the pH of the solution will decrease 
C) the solution will not have pH 
D) the pH of the solution will not change 
E) NH4Cl cannot be added to NH3

Question 16

Twenty-five milliliters of 0.10 M HCl(aq)is titrated with 0.10 M NaOH(aq).What is the pH after 15 mL of NaOH(aq)has been added?

Accepted Answer

A) 1.4 
B) 1.2 
C) 1.0 
D) 2.0 
E) 1.6 
A) 1.4 
B) 1.2 
C) 1.0 
D) 2.0 
E) 1.6

Question 17

What volume in mL of 2.0 M H2SO4(aq)is needed to neutralize 7.8 g of Al(OH)3(78.0 g/mol)? Al2(SO4)3(aq)and water are the titration products.

Accepted Answer

A) 150 mL 
B) 75 mL 
C) 300 mL 
D) 500 mL 
E) 250 mL 
A) 150 mL 
B) 75 mL 
C) 300 mL 
D) 500 mL 
E) 250 mL

Question 18

The neutralization of a weak acid with a strong base will produce a longer vertical section of a titration curve than will a strong acid with a strong base.

Accepted Answer

A) True 
 B)False

Question 19

What volume in mL of 0.05 M NaOH(aq)would have to be added to 50.0 mL of 0.10 M H2SO4(aq)in order to affect complete neutralization of the acid?

Accepted Answer

A) 50 mL 
B) 20 mL 
C) 100 mL 
D) 150 mL 
E) 200 mL 
A) 50 mL 
B) 20 mL 
C) 100 mL 
D) 150 mL 
E) 200 mL

Question 20

The solution that is added from the buret during a titration is the:

Accepted Answer

A) buffer 
B) titrant 
C) indicator 
D) base 
E) titrator 
A) buffer 
B) titrant 
C) indicator 
D) base 
E) titrator

Exam 17: Additional Aspects of Acidbase Equilibria

What is the pH of a 1.0 M aqueous solution of trisodium phosphate? Ka1 = 7.1 × 10-3,Ka2 = 6.3 × 10-8, Ka3 = 4.2 × 10-13

An aqueous solution of an unknown acid had a pH of 3.70.Titration of a 25.0 mL aliquot of the acid solution required 21.7 mL of 0.104 M aqueous sodium hydroxide for complete reaction.Assuming that the acid is monoprotic,what is its ionization constant?

What is the pH of the resulting solution if 25.00 mL of 0.10 mol L-1 aqueous acetic acid is added to 10.00 mL of 0.10 mol L-1 NaOH(aq)? Assume that the volumes of the solutions are additive.Ka = 1.8 × 10-5 for CH3COOH

A handbook states that to prepare a particular buffer solution mix 39.0 mL of 0.20 M aqueous NaH2PO4 with 61.0 mL of 0.20 M aqueous Na2HPO4.What will be the pH of this buffer? For phosphoric acid Ka2= 6.2 × 10-8

The common ion in an aqueous solution of a weak acid and a strong acid is the hydronium ion.

Determine the [C2H3O2-] of the following aqueous solution.Initial concentrations are given. [HC2H3O2] = 0.250 M,[HI] = 0.120 M Ka (acetic acid)= 1.8 × 10-5

How many millilitres of 0.120 mol L-1 NaOH(aq)are required to titrate 50.0 mL of 0.0998 mol L-1 aqueous butanoic acid to the equivalence point? Butanoic acid is monoprotic.The Of butanoic acid is 1.5 × 10-5.

A weak acid has Ka = 4.2 × 10-3.If [A-] = 2.0 M,what must [HA] be so that [H+] = 2.1 × 10-3 M?

The following compounds are available as 0.10 M aqueous solutions: pyridine (pKb = 8.82),triethylamine (pKb = 3.25),HClO4,phenol (pKa = 9.96),HClO (pKa = 7.54),NH3 (pKb = 4.74)and NaOH.Identify two solutions that could be used to prepare a buffer with a pH of approximately 5.

What is the pH of an aqueous solution prepared by mixing 50.00 mL of 0.10 mol L-1 methylamine,CH3NH2,with 20.00 mL of 0.10 mol L-1 methylammonium chloride,CH3NH3Cl? Assume that the volume of the solutions are additive and that Kb = 3.70 × 10-4 for methylamine.

What is the [H3O+] of an aqueous solution measured to be 0.20 M in sodium acetate and 0.40 M in acetic acid? (Ka = 1.8 × 10-5)

How many mL of 0.200 M aqueous acetic acid are mixed with 13.2 mL of 0.200 M aqueous sodium acetate to give a buffer with pH = 4.2? (Ka for acetic acid is 1.8 × 10-5)

What is the pH of a 1.0 M aqueous solution of Na2SO3? Ka1 = 1.3 × 10-2,Ka2 = 6.2 × 10-8?

Determine the pH of the following aqueous solution.Initial concentrations are given. [NaCHO2] = 0.815 M,[HBr] = 0.105 M,Ka for HCHO2= 1.8 × 10-4

If some NH4Cl is added to an aqueous solution of NH3:

Twenty-five milliliters of 0.10 M HCl(aq)is titrated with 0.10 M NaOH(aq).What is the pH after 15 mL of NaOH(aq)has been added?

What volume in mL of 2.0 M H2SO4(aq)is needed to neutralize 7.8 g of Al(OH)3(78.0 g/mol)? Al2(SO4)3(aq)and water are the titration products.

The neutralization of a weak acid with a strong base will produce a longer vertical section of a titration curve than will a strong acid with a strong base.

What volume in mL of 0.05 M NaOH(aq)would have to be added to 50.0 mL of 0.10 M H2SO4(aq)in order to affect complete neutralization of the acid?

The solution that is added from the buret during a titration is the:

Matter: Its Properties and Measurement

Atoms and the Atomic Theory

Chemical Compounds

Chemical Reactions

Introduction to Reactions in Aqueous Solutions

Gases

Thermochemistry

Electrons in Atoms

The Periodic Table and Some Atomic Properties

Chemical Bonding I: Basic Concepts

Chemical Bonding Ii: Valence Bond and Molecular Orbital Theories

Intermolecular Forces: Liquids and Solids

Spontaneous Change: Entropy and Gibbs Energy

Solutions and Their Physical Properties

Principles of Chemical Equilibrium

Acids and Bases

Solubility and Complex-Ion Equilibria

Electrochemistry

Chemical Kinetics

Chemistry of the Main-Group Elements I: Groups 1,2,13,and 14

Chemistry of the Main-Group Elements Ii: Groups 18,17,16,15,and Hydrogen

The Transition Elements

Complex Ions and Coordination Compounds

Nuclear Chemistry

Structures of Organic Compounds

Reactions of Organic Compounds

Chemistry of the Living State

Filters

What is the pH of a 1.0 M aqueous solution of trisodium phosphate? K_a1 = 7.1 × 10^-3,K_a2 = 6.3 × 10^-8, K_a3 = 4.2 × 10^-13

What is the pH of the resulting solution if 25.00 mL of 0.10 mol L^-1 aqueous acetic acid is added to 10.00 mL of 0.10 mol L^-1 NaOH(aq)? Assume that the volumes of the solutions are additive.K_a = 1.8 × 10^-5for CH₃COOH

A handbook states that to prepare a particular buffer solution mix 39.0 mL of 0.20 M aqueous NaH₂PO₄ with 61.0 mL of 0.20 M aqueous Na₂HPO₄.What will be the pH of this buffer? For phosphoric acid Ka₂= 6.2 × 10^-8

Determine the [C₂H₃O₂^-] of the following aqueous solution.Initial concentrations are given. [HC₂H₃O₂] = 0.250 M,[HI] = 0.120 M K_a (acetic acid)= 1.8 × 10^-5

How many millilitres of 0.120 mol L^-1 NaOH(aq)are required to titrate 50.0 mL of 0.0998 mol L^-1 aqueous butanoic acid to the equivalence point? Butanoic acid is monoprotic.The Of butanoic acid is 1.5 × 10^-5.

A weak acid has K_a = 4.2 × 10^-3.If [A^-] = 2.0 M,what must [HA] be so that [H⁺] = 2.1 × 10^-3 M?

The following compounds are available as 0.10 M aqueous solutions: pyridine (pK_b = 8.82),triethylamine (pK_b = 3.25),HClO₄,phenol (pK_a = 9.96),HClO (pK_a = 7.54),NH₃ (pK_b = 4.74)and NaOH.Identify two solutions that could be used to prepare a buffer with a pH of approximately 5.

What is the pH of an aqueous solution prepared by mixing 50.00 mL of 0.10 mol L^-1 methylamine,CH₃NH₂,with 20.00 mL of 0.10 mol L^-1 methylammonium chloride,CH₃NH₃Cl? Assume that the volume of the solutions are additive and that K_b = 3.70 × 10^-4 for methylamine.

What is the [H₃O⁺] of an aqueous solution measured to be 0.20 M in sodium acetate and 0.40 M in acetic acid? (K_a = 1.8 × 10^-5)

How many mL of 0.200 M aqueous acetic acid are mixed with 13.2 mL of 0.200 M aqueous sodium acetate to give a buffer with pH = 4.2? (K_a for acetic acid is 1.8 × 10^-5)

What is the pH of a 1.0 M aqueous solution of Na₂SO₃? K_a1 = 1.3 × 10^-2,K_a2 = 6.2 × 10^-8?

Determine the pH of the following aqueous solution.Initial concentrations are given. [NaCHO₂] = 0.815 M,[HBr] = 0.105 M,K_a for HCHO₂= 1.8 × 10^-4

If some NH₄Cl is added to an aqueous solution of NH₃:

What volume in mL of 2.0 M H₂SO₄(aq)is needed to neutralize 7.8 g of Al(OH)₃(78.0 g/mol)? Al₂(SO₄)₃(aq)and water are the titration products.

What volume in mL of 0.05 M NaOH(aq)would have to be added to 50.0 mL of 0.10 M H₂SO₄(aq)in order to affect complete neutralization of the acid?