Question 1

Effects that stabilize the conjugate base of an acid produce a stronger acid. Describe two of these effects.

Accepted Answer

The conjugate base of an acid has a grea

Question 2

Which sketch best represents the qualitative molecular view of an aqueous solution of sodium hydroxide? (Water molecules are not shown explicitly.)

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)

Question 3

Vitamin C, which is ascorbic acid, is a diprotic acid with   F1F1F1S1F1F1F10 5.00 and   F1F1F1S1F1F1F10 11.3. What is the pH of a 0.125 M solution of ascorbic acid?

Accepted Answer

A) 2.95 
B) 3.05 
C) 5.00 
D) 6.10 
E) 3.54 
A) 2.95 
B) 3.05 
C) 5.00 
D) 6.10 
E) 3.54

Question 4

What is Kb for the benzoate ion, given that the Ka for benzoic acid is 6.46 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F105?

Accepted Answer

A) 1.55 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1010 
B) 6.46 F1F1F1S1F1F1F10 10 9 
C) 6.46 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1019 
D) 3.52 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F109 
E) 7.43 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F105 
A) 1.55 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1010 
B) 6.46 F1F1F1S1F1F1F10 10 9 
C) 6.46 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1019 
D) 3.52 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F109 
E) 7.43 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F105

Question 5

Identify the weakest and strongest acids in the group below. The weakest acid is listed first in the responses. HCl, H2S, PH3

Accepted Answer

A) HCl F1F1F1S1F1F1F10 H2S 
B) HCl F1F1F1S1F1F1F10 PH3 
C) H2S F1F1F1S1F1F1F10 HCl 
D) H2S F1F1F1S1F1F1F10 PH3 
E) PH3 F1F1F1S1F1F1F10 HCl 
A) HCl F1F1F1S1F1F1F10 H2S 
B) HCl F1F1F1S1F1F1F10 PH3 
C) H2S F1F1F1S1F1F1F10 HCl 
D) H2S F1F1F1S1F1F1F10 PH3 
E) PH3 F1F1F1S1F1F1F10 HCl

Question 6

What is the concentration of ammonium ion in a 0.150 M solution of ammonia? The Kb value for ammonia is 1.80 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F105.

Accepted Answer

A) 0.146 M 
B) 0.148 M 
C) 2.34 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F105 M 
D) 1.63 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F103 M 
E) 4.20 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F103 M 
A) 0.146 M 
B) 0.148 M 
C) 2.34 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F105 M 
D) 1.63 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F103 M 
E) 4.20 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F103 M

Question 7

Three acids found in foods are lactic acid (in milk products), oxalic acid (in rhubarb), and malic acid (in apples). The pKa values are LA F1F1F1S1F1F1F10 3.88, OA F1F1F1S1F1F1F10 1.23, and MA F1F1F1S1F1F1F10 3.40. Which list has the conjugate bases of these acids in order of decreasing strength?

Accepted Answer

A) lactate F1F1F1S1F1F1F10 oxalate F1F1F1S1F1F1F10 malate 
B) oxalate F1F1F1S1F1F1F10 malate F1F1F1S1F1F1F10 lactate 
C) lactate F1F1F1S1F1F1F10 malate F1F1F1S1F1F1F10 oxalate 
D) oxalate F1F1F1S1F1F1F10 lactate F1F1F1S1F1F1F10 malate 
E) malate F1F1F1S1F1F1F10 lactate F1F1F1S1F1F1F10 oxalate 
A) lactate F1F1F1S1F1F1F10 oxalate F1F1F1S1F1F1F10 malate 
B) oxalate F1F1F1S1F1F1F10 malate F1F1F1S1F1F1F10 lactate 
C) lactate F1F1F1S1F1F1F10 malate F1F1F1S1F1F1F10 oxalate 
D) oxalate F1F1F1S1F1F1F10 lactate F1F1F1S1F1F1F10 malate 
E) malate F1F1F1S1F1F1F10 lactate F1F1F1S1F1F1F10 oxalate

Question 8

Aqueous solutions of ________ are acidic.

Accepted Answer

A) NaF 
B) CsCN 
C) MgCl2 
D) NH4I 
E) KI 
A) NaF 
B) CsCN 
C) MgCl2 
D) NH4I 
E) KI

Question 9

Which of the following is the conjugate acid of the hydrogen phosphate ion, HPO42F1F1F1S1F1F1F10?

Accepted Answer

A) H3PO4 
B) H2PO4F1F1F1S1F1F1F10 
C) HPO42F1F1F1S1F1F1F10 
D) PO43F1F1F1S1F1F1F10 
E) H3OF1F1F1S1F1F1F10 
A) H3PO4 
B) H2PO4F1F1F1S1F1F1F10 
C) HPO42F1F1F1S1F1F1F10 
D) PO43F1F1F1S1F1F1F10 
E) H3OF1F1F1S1F1F1F10

Question 10

What is the pH of a 0.15 M solution of ammonium bromide? The Kb value for ammonia is 1.8 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F105.

Accepted Answer

A) 11.22 
B) 7.00 
C) 2.78 
D) 5.04 
E) 10.08 
A) 11.22 
B) 7.00 
C) 2.78 
D) 5.04 
E) 10.08

Question 11

A cup of coffee has a hydroxide ion concentration of 1.0 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1010 M. What is the pH of this coffee?

Accepted Answer

A) 1.0 F1F1F1S1F1F1F1010F1F1F1S1F1F1F104 
B) 4 
C) 10 
D) 7 
E) (F1F1F1S1F1F1F1010) 
A) 1.0 F1F1F1S1F1F1F1010F1F1F1S1F1F1F104 
B) 4 
C) 10 
D) 7 
E) (F1F1F1S1F1F1F1010)

Question 12

The base ionization constant Kb describes which of the following reactions for a weak base, B, in aqueous solution?

Accepted Answer

A) B F1F1F1S1F1F1F10 HF1F1F1S1F1F1F10 
    BHF1F1F1S1F1F1F10 
B) B F1F1F1S1F1F1F10 H3OF1F1F1S1F1F1F10   BHF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H2O 
C) B F1F1F1S1F1F1F10 H2O   BHF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 OHF1F1F1S1F1F1F10 
D) B F1F1F1S1F1F1F10 OHF1F1F1S1F1F1F10   BHF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 O2F1F1F1S1F1F1F10 
E) BHF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 OHF1F1F1S1F1F1F10   B F1F1F1S1F1F1F10 H2O 
A) B F1F1F1S1F1F1F10 HF1F1F1S1F1F1F10 
    BHF1F1F1S1F1F1F10 
B) B F1F1F1S1F1F1F10 H3OF1F1F1S1F1F1F10   BHF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H2O 
C) B F1F1F1S1F1F1F10 H2O   BHF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 OHF1F1F1S1F1F1F10 
D) B F1F1F1S1F1F1F10 OHF1F1F1S1F1F1F10   BHF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 O2F1F1F1S1F1F1F10 
E) BHF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 OHF1F1F1S1F1F1F10   B F1F1F1S1F1F1F10 H2O

Question 13

What is the pH of a 0.200 M solution of methylamine? The Kb value for methylamine is 4.38 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F104.

Accepted Answer

A) 2.04 
B) (F1F1F1S1F1F1F101.33) 
C) 10.53 
D) 15.33 
E) 11.96 
A) 2.04 
B) (F1F1F1S1F1F1F101.33) 
C) 10.53 
D) 15.33 
E) 11.96

Question 14

Use the following acid ionization constants to identify the correct decreasing order of base strengths for the conjugate bases. HF
Ka F1F1F1S1F1F1F10 7.2 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F104
HNO2
Ka F1F1F1S1F1F1F10 4.5 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F104
HCN
Ka F1F1F1S1F1F1F10 6.2 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1010

Accepted Answer

A) CNF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 NO2F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 FF1F1F1S1F1F1F10 
B) NO2F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 FF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 CNF1F1F1S1F1F1F10 
C) FF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 CNF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 NO2F1F1F1S1F1F1F10 
D) FF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 NO2F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 CNF1F1F1S1F1F1F10 
E) NO2F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 CNF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 FF1F1F1S1F1F1F10 
A) CNF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 NO2F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 FF1F1F1S1F1F1F10 
B) NO2F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 FF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 CNF1F1F1S1F1F1F10 
C) FF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 CNF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 NO2F1F1F1S1F1F1F10 
D) FF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 NO2F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 CNF1F1F1S1F1F1F10 
E) NO2F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 CNF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 FF1F1F1S1F1F1F10

Question 15

Which of the following is the conjugate base of the hydrogen carbonate ion, HCO3F1F1F1S1F1F1F10?

Accepted Answer

A) H2CO3 
B) HCO3F1F1F1S1F1F1F10 
C) CO32F1F1F1S1F1F1F10 
D) OHF1F1F1S1F1F1F10 
E) H3CO3F1F1F1S1F1F1F10 
A) H2CO3 
B) HCO3F1F1F1S1F1F1F10 
C) CO32F1F1F1S1F1F1F10 
D) OHF1F1F1S1F1F1F10 
E) H3CO3F1F1F1S1F1F1F10

Question 16

What is the pOH of a 0.125 M solution of hydroxylamine? The Kb value for hydroxylamine is 1.1 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F108.

Accepted Answer

A) 4.43 
B) 3.47 
C) 5.57 
D) 10.53 
E) 9.57 
A) 4.43 
B) 3.47 
C) 5.57 
D) 10.53 
E) 9.57

Question 17

In evaluating the pH of an aqueous weak acid solution, ________ usually can be ignored.

Accepted Answer

A) the concentration of the weak acid 
B) the concentration of hydronium ion produced by the autoionization of water 
C) the reaction of the weak acid with water 
D) the concentration of the ionized hydronium ion 
E) the concentration of the conjugate base 
A) the concentration of the weak acid 
B) the concentration of hydronium ion produced by the autoionization of water 
C) the reaction of the weak acid with water 
D) the concentration of the ionized hydronium ion 
E) the concentration of the conjugate base

Question 18

You decide to put your growing knowledge of chemistry to profit by making and selling boutique soaps that are ultra mild and have an almost neutral pH. What is the pH of your best liquid soap made from a fatty acid that has a pKa value of 2.0? The concentration of the active ingredient, a fatty acid salt, is 1.0 M.

Accepted Answer

A) 2.0 
B) 7.5 
C) 8.0 
D) 8.5 
E) 9.0 
A) 2.0 
B) 7.5 
C) 8.0 
D) 8.5 
E) 9.0

Question 19

The first disinfectant used by Joseph Lister was called carbolic acid. This substance now is known as phenol, C6H5OH (pKa F1F1F1S1F1F1F10 10.0). What is the pH of a 0.10 M solution of phenol?

Accepted Answer

A) 3.5 
B) 10.0 
C) 6.5 
D) 5.5 
E) 4.5 
A) 3.5 
B) 10.0 
C) 6.5 
D) 5.5 
E) 4.5

Question 20

The analysis label on a 500 mL bottle of Fiji natural artesian water reports pH F1F1F1S1F1F1F10 7.5 and 140 mg of bicarbonates, HCO3F1F1F1S1F1F1F10. Calculate the pH expected as a result of the bicarbonates to see if these two numbers are consistent with each other. (Kb F1F1F1S1F1F1F10 2.4 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F108 for HCO3F1F1F1S1F1F1F10)

Accepted Answer

A) 7.5 
B) 5.0 
C) 9.6 
D) 4.4 
E) 9.0 
A) 7.5 
B) 5.0 
C) 9.6 
D) 4.4 
E) 9.0

Exam 15: Acidbase Equilibria: Proton Transfer in Biological Systems

Effects that stabilize the conjugate base of an acid produce a stronger acid. Describe two of these effects.

Which sketch best represents the qualitative molecular view of an aqueous solution of sodium hydroxide? (Water molecules are not shown explicitly.)

Vitamin C, which is ascorbic acid, is a diprotic acid with  5.00 and  11.3. What is the pH of a 0.125 M solution of ascorbic acid?

What is Kb for the benzoate ion, given that the Ka for benzoic acid is 6.46  105?

Identify the weakest and strongest acids in the group below. The weakest acid is listed first in the responses. HCl, H2S, PH3

What is the concentration of ammonium ion in a 0.150 M solution of ammonia? The Kb value for ammonia is 1.80  105.

Three acids found in foods are lactic acid (in milk products), oxalic acid (in rhubarb), and malic acid (in apples). The pKa values are LA  3.88, OA  1.23, and MA  3.40. Which list has the conjugate bases of these acids in order of decreasing strength?

Aqueous solutions of ________ are acidic.

Which of the following is the conjugate acid of the hydrogen phosphate ion, HPO42?

What is the pH of a 0.15 M solution of ammonium bromide? The Kb value for ammonia is 1.8  105.

A cup of coffee has a hydroxide ion concentration of 1.0  1010 M. What is the pH of this coffee?

The base ionization constant Kb describes which of the following reactions for a weak base, B, in aqueous solution?

What is the pH of a 0.200 M solution of methylamine? The Kb value for methylamine is 4.38  104.

Use the following acid ionization constants to identify the correct decreasing order of base strengths for the conjugate bases. HF Ka  7.2  104 HNO2 Ka  4.5  104 HCN Ka  6.2  1010

Which of the following is the conjugate base of the hydrogen carbonate ion, HCO3?

What is the pOH of a 0.125 M solution of hydroxylamine? The Kb value for hydroxylamine is 1.1  108.

In evaluating the pH of an aqueous weak acid solution, ________ usually can be ignored.

The first disinfectant used by Joseph Lister was called carbolic acid. This substance now is known as phenol, C6H5OH (pKa  10.0). What is the pH of a 0.10 M solution of phenol?

The analysis label on a 500 mL bottle of Fiji natural artesian water reports pH  7.5 and 140 mg of bicarbonates, HCO3. Calculate the pH expected as a result of the bicarbonates to see if these two numbers are consistent with each other. (Kb  2.4  108 for HCO3)

Matter and Energy: The Origin of the Universe

Atoms, Ions, and Molecules: Matter Starts Here

Stoichiometry: Mass, Formulas, and Reactions

Solution Chemistry: The Hydrosphere

Thermochemistry: Energy Changes in Reactions

Properties of Gases: The Air We Breathe

A Quantum Model of Atoms: Waves and Particles

Chemical Bonds: What Makes a Gas a Greenhouse Gas

Molecular Geometry: Shape Determines Function

Intermolecular Forces: The Uniqueness of Water

Solutions: Properties and Behavior

Solids: Crystals, Alloys, and Polymers

Chemical Kinetics: Reactions in the Atmosphere

Chemical Equilibrium: How Much Product Does a Reaction Really Make

Additional Aqueous Equilibria: Chemistry and the Oceans

Thermodynamics: Spontaneous and Nonspontaneous Reactions and Processes

Electrochemistry: The Quest for Clean Energy

Nuclear Chemistry: Applications to Energy and Medicine

Organic and Biological Molecules: the Compounds of Life

The Main Group Elements: Life and the Periodic Table

Transition Metals: Biological and Medical Applications

Filters

What is K_b for the benzoate ion, given that the K_a for benzoic acid is 6.46  10^⁵?

Identify the weakest and strongest acids in the group below. The weakest acid is listed first in the responses. HCl, H₂S, PH₃

What is the concentration of ammonium ion in a 0.150 M solution of ammonia? The K_b value for ammonia is 1.80  10^⁵.

Three acids found in foods are lactic acid (in milk products), oxalic acid (in rhubarb), and malic acid (in apples). The pK_a values are LA  3.88, OA  1.23, and MA  3.40. Which list has the conjugate bases of these acids in order of decreasing strength?

Which of the following is the conjugate acid of the hydrogen phosphate ion, HPO₄²^?

What is the pH of a 0.15 M solution of ammonium bromide? The K_b value for ammonia is 1.8  10^⁵.

A cup of coffee has a hydroxide ion concentration of 1.0  10^¹⁰ M. What is the pH of this coffee?

The base ionization constant K_b describes which of the following reactions for a weak base, B, in aqueous solution?

What is the pH of a 0.200 M solution of methylamine? The K_b value for methylamine is 4.38  10^⁴.

Use the following acid ionization constants to identify the correct decreasing order of base strengths for the conjugate bases. HF K_a  7.2  10^⁴ HNO₂ K_a  4.5  10^⁴ HCN K_a  6.2  10^¹⁰

Which of the following is the conjugate base of the hydrogen carbonate ion, HCO₃^?

What is the pOH of a 0.125 M solution of hydroxylamine? The K_b value for hydroxylamine is 1.1  10^⁸.

The first disinfectant used by Joseph Lister was called carbolic acid. This substance now is known as phenol, C₆H₅OH (pK_a  10.0). What is the pH of a 0.10 M solution of phenol?

The analysis label on a 500 mL bottle of Fiji natural artesian water reports pH  7.5 and 140 mg of bicarbonates, HCO₃^. Calculate the pH expected as a result of the bicarbonates to see if these two numbers are consistent with each other. (K_b  2.4  10^⁸ for HCO₃^)