Question 1

What is the pH of a 0.055 M solution of sodium cyanide? The Ka value for hydrocyanic acid is 6.2 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1010.

Accepted Answer

A) 10.97 
B) 5.23 
C) 8.77 
D) 3.03 
E) 10.08 
A) 10.97 
B) 5.23 
C) 8.77 
D) 3.03 
E) 10.08

Question 2

A substance that can act as both an acid and base is ________

Accepted Answer

A) amphibious. 
B) amphiprotic. 
C) bacidic. 
D) androgynous. 
E) acibasic. 
A) amphibious. 
B) amphiprotic. 
C) bacidic. 
D) androgynous. 
E) acibasic.

Question 3

Identify the weakest and strongest acids in the group below. The weakest acid is listed first in the responses. H2O, H2S, H2Se

Accepted Answer

A) H2Se F1F1F1S1F1F1F10 H2S 
B) H2Se F1F1F1S1F1F1F10 H2O 
C) H2S F1F1F1S1F1F1F10 H2Se 
D) H2O F1F1F1S1F1F1F10 H2Se 
E) H2O F1F1F1S1F1F1F10 H2S 
A) H2Se F1F1F1S1F1F1F10 H2S 
B) H2Se F1F1F1S1F1F1F10 H2O 
C) H2S F1F1F1S1F1F1F10 H2Se 
D) H2O F1F1F1S1F1F1F10 H2Se 
E) H2O F1F1F1S1F1F1F10 H2S

Question 4

Methylamine (CH3NH2) is a weakly basic compound. Calculate the Kb for methylamine if a 0.253 M solution is 4.07% ionized.

Accepted Answer

A) 2.29 F1F1F1S1F1F1F10 103 
B) 4.37 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F104 
C) 5.72 
D) 4.24 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F102 
E) 4.19 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F104 
A) 2.29 F1F1F1S1F1F1F10 103 
B) 4.37 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F104 
C) 5.72 
D) 4.24 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F102 
E) 4.19 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F104

Question 5

What is the pH of a 0.500 M solution of trimethylamine (pKb F1F1F1S1F1F1F10 4.13)?

Accepted Answer

A) 2.22 
B) 11.8 
C) 0.00609 
D) 4.42 
E) 5.91 
A) 2.22 
B) 11.8 
C) 0.00609 
D) 4.42 
E) 5.91

Question 6

Phosphoric acid is a triprotic acid, ionizing in the following sequential steps: H3PO4 F1F1F1S1F1F1F10 H2O   H2PO4F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H3OF1F1F1S1F1F1F10   H2PO4F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H2O   HPO42F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H3OF1F1F1S1F1F1F10   HPO42F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H2O   PO43F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H3OF1F1F1S1F1F1F10   What is the Kb expression for the base, dihydrogen phosphate?

Accepted Answer

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

Question 7

What is the concentration of the acetate ion in a 1.00 M CH3COOH solution given that the Ka of CH3COOH is 1.8 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F105?

Accepted Answer

A) 4.20 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F103 M 
B) 0.996 M 
C) 1.00 M 
D) 2.84 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F104 M 
E) 5.62 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F105 M 
A) 4.20 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F103 M 
B) 0.996 M 
C) 1.00 M 
D) 2.84 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F104 M 
E) 5.62 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F105 M

Question 8

What is the concentration of [OHF1F1F1S1F1F1F10] in a 0.20 M solution of ammonia? The Kb value for ammonia is 1.8 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F105.

Accepted Answer

A) 3.6 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F106 M 
B) 1.8 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F105 M 
C) 0.20 M 
D) 1.9 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F103 M 
E) 4.2 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F104 M 
A) 3.6 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F106 M 
B) 1.8 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F105 M 
C) 0.20 M 
D) 1.9 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F103 M 
E) 4.2 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F104 M

Question 9

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

Accepted Answer

A) 9.14 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F103 
B) 1.09 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1012 
C) 5.24 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1014 
D) 1.00 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F107 
E) 1.91 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F101 
A) 9.14 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F103 
B) 1.09 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1012 
C) 5.24 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1014 
D) 1.00 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F107 
E) 1.91 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F101

Question 10

A solution with a pH of 9.50 has a pOH of ________

Accepted Answer

A) 9.50. 
B) 0.50. 
C) 4.50. 
D) 23.5. 
E) 19.0. 
A) 9.50. 
B) 0.50. 
C) 4.50. 
D) 23.5. 
E) 19.0.

Question 11

Which ending to the statement is not correct? The weak acid HY will be stronger than the weak acid HZ if ________

Accepted Answer

A) more Lewis resonance structures can be written for the Y group than for the Z group. 
B) Y is more electronegative than Z. 
C) the Y group has more oxygen atoms than the Z group. 
D) the HF1F1F1S1F1F1F10Y bond is weaker than the HF1F1F1S1F1F1F10Z bond and other things are about the same. 
E) the Y group contains Br rather than Cl, which is in the Z group. 
A) more Lewis resonance structures can be written for the Y group than for the Z group. 
B) Y is more electronegative than Z. 
C) the Y group has more oxygen atoms than the Z group. 
D) the HF1F1F1S1F1F1F10Y bond is weaker than the HF1F1F1S1F1F1F10Z bond and other things are about the same. 
E) the Y group contains Br rather than Cl, which is in the Z group.

Question 12

When pure water autoionizes, which ions are produced?

Accepted Answer

A) O2F1F1F1S1F1F1F10, OHF1F1F1S1F1F1F10, H3OF1F1F1S1F1F1F10, and H2OF1F1F1S1F1F1F10 
B) OHF1F1F1S1F1F1F10 and H3OF1F1F1S1F1F1F10 
C) O2F1F1F1S1F1F1F10 and H4O2F1F1F1S1F1F1F10 
D) HF1F1F1S1F1F1F10 and OHF1F1F1S1F1F1F10 
E) 2HF1F1F1S1F1F1F10 and O2F1F1F1S1F1F1F10 
A) O2F1F1F1S1F1F1F10, OHF1F1F1S1F1F1F10, H3OF1F1F1S1F1F1F10, and H2OF1F1F1S1F1F1F10 
B) OHF1F1F1S1F1F1F10 and H3OF1F1F1S1F1F1F10 
C) O2F1F1F1S1F1F1F10 and H4O2F1F1F1S1F1F1F10 
D) HF1F1F1S1F1F1F10 and OHF1F1F1S1F1F1F10 
E) 2HF1F1F1S1F1F1F10 and O2F1F1F1S1F1F1F10

Question 13

Which one of the following is a conjugate acid-base pair?

Accepted Answer

A) NaF and FF1F1F1S1F1F1F10 
B) HNO3 and HNO2 
C) HI and IF1F1F1S1F1F1F10 
D) NH4F1F1F1S1F1F1F10 and NH2F1F1F1S1F1F1F10 
E) H2O and H2O2 
A) NaF and FF1F1F1S1F1F1F10 
B) HNO3 and HNO2 
C) HI and IF1F1F1S1F1F1F10 
D) NH4F1F1F1S1F1F1F10 and NH2F1F1F1S1F1F1F10 
E) H2O and H2O2

Question 14

The pH of an ammonia solution is 11.6, and the solution has a concentration of about 0.20 M. The pKb of ammonia is 4.75. What is the percent ionization of ammonia?

Accepted Answer

A) 2.0% 
B) 2.3% 
C) 1.2% 
D) 0.95% 
E) 5.4% 
A) 2.0% 
B) 2.3% 
C) 1.2% 
D) 0.95% 
E) 5.4%

Question 15

Four solutions have pH values of 3, 5, 8, and 10. Arrange these in order of increasing acidity, and identify those that are acidic, basic, and neutral.

Accepted Answer

Increasing acidity: 10 F1F1F1S

Question 16

When [HF1F1F1S1F1F1F10] F1F1F1S1F1F1F10 1.0 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F107 M in water at 25F1F1F1S1F1F1F10C, then ________

Accepted Answer

A) pH F1F1F1S1F1F1F10 1. 
B) pH F1F1F1S1F1F1F10 10F1F1F1S1F1F1F107. 
C) [OHF1F1F1S1F1F1F10] F1F1F1S1F1F1F10 1.0 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F107 M. 
D) [OHF1F1F1S1F1F1F10] F1F1F1S1F1F1F10 1.0 F1F1F1S1F1F1F10 107 M. 
E) [OHF1F1F1S1F1F1F10] F1F1F1S1F1F1F10 0 M. 
A) pH F1F1F1S1F1F1F10 1. 
B) pH F1F1F1S1F1F1F10 10F1F1F1S1F1F1F107. 
C) [OHF1F1F1S1F1F1F10] F1F1F1S1F1F1F10 1.0 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F107 M. 
D) [OHF1F1F1S1F1F1F10] F1F1F1S1F1F1F10 1.0 F1F1F1S1F1F1F10 107 M. 
E) [OHF1F1F1S1F1F1F10] F1F1F1S1F1F1F10 0 M.

Question 17

Which of the following salts produce(s) a basic solution when dissolved in water? NH4Cl
K2S
NaCN
CsNO3

Accepted Answer

A) I only 
B) II only 
C) I and IV only 
D) II and III only 
E) III and IV only 
A) I only 
B) II only 
C) I and IV only 
D) II and III only 
E) III and IV only

Question 18

A solution with a pOH of 6.92 has an [OHF1F1F1S1F1F1F10] concentration of ________

Accepted Answer

A) 1.20 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F107 M. 
B) 9.2 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F106 M. 
C) 6.8 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F106 M. 
D) 7.08 M. 
E) 6.92 M. 
A) 1.20 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F107 M. 
B) 9.2 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F106 M. 
C) 6.8 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F106 M. 
D) 7.08 M. 
E) 6.92 M.

Question 19

The degree of ionization of a weak acid ________
I. varies with the concentration of the acid.
II. depends on which weak acid it is.
III. is 100%.
IV. is greater than 50% but less than 100%.

Accepted Answer

A) I only 
B) II only 
C) III only 
D) both I and II 
E) IV only 
A) I only 
B) II only 
C) III only 
D) both I and II 
E) IV only

Question 20

Which one of the following is not a strong base?

Accepted Answer

A) lithium hydroxide, LiOH 
B) sodium hydroxide, NaOH 
C) potassium hydroxide, KOH 
D) calcium hydroxide, Ca(OH)2 
E) ammonium hydroxide, NH4OH 
A) lithium hydroxide, LiOH 
B) sodium hydroxide, NaOH 
C) potassium hydroxide, KOH 
D) calcium hydroxide, Ca(OH)2 
E) ammonium hydroxide, NH4OH

Exam 15: Acidbase Equilibria: Proton Transfer in Biological Systems

What is the pH of a 0.055 M solution of sodium cyanide? The Ka value for hydrocyanic acid is 6.2  1010.

A substance that can act as both an acid and base is ________

Identify the weakest and strongest acids in the group below. The weakest acid is listed first in the responses. H2O, H2S, H2Se

Methylamine (CH3NH2) is a weakly basic compound. Calculate the Kb for methylamine if a 0.253 M solution is 4.07% ionized.

What is the pH of a 0.500 M solution of trimethylamine (pKb  4.13)?

Phosphoric acid is a triprotic acid, ionizing in the following sequential steps: H3PO4  H2O H2PO4  H3O H2PO4  H2O HPO42  H3O HPO42  H2O PO43  H3O What is the Kb expression for the base, dihydrogen phosphate?

What is the concentration of the acetate ion in a 1.00 M CH3COOH solution given that the Ka of CH3COOH is 1.8  105?

What is the concentration of [OH] in a 0.20 M solution of ammonia? The Kb value for ammonia is 1.8  105.

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

A solution with a pH of 9.50 has a pOH of ________

Which ending to the statement is not correct? The weak acid HY will be stronger than the weak acid HZ if ________

When pure water autoionizes, which ions are produced?

Which one of the following is a conjugate acid-base pair?

The pH of an ammonia solution is 11.6, and the solution has a concentration of about 0.20 M. The pKb of ammonia is 4.75. What is the percent ionization of ammonia?

Four solutions have pH values of 3, 5, 8, and 10. Arrange these in order of increasing acidity, and identify those that are acidic, basic, and neutral.

When [H]  1.0  107 M in water at 25C, then ________

Which of the following salts produce(s) a basic solution when dissolved in water? NH4Cl K2S NaCN CsNO3

A solution with a pOH of 6.92 has an [OH] concentration of ________

The degree of ionization of a weak acid ________ I. varies with the concentration of the acid. II. depends on which weak acid it is. III. is 100%. IV. is greater than 50% but less than 100%.

Which one of the following is not a strong base?

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 the pH of a 0.055 M solution of sodium cyanide? The K_a value for hydrocyanic acid is 6.2  10^¹⁰.

Identify the weakest and strongest acids in the group below. The weakest acid is listed first in the responses. H₂O, H₂S, H₂Se

Methylamine (CH₃NH₂) is a weakly basic compound. Calculate the K_b for methylamine if a 0.253 M solution is 4.07% ionized.

What is the pH of a 0.500 M solution of trimethylamine (pK_b  4.13)?

Phosphoric acid is a triprotic acid, ionizing in the following sequential steps: H₃PO₄  H₂O H₂PO₄^  H₃O^ H₂PO₄^  H₂O HPO₄²^  H₃O^ HPO₄²^  H₂O PO₄³^  H₃O^ What is the K_b expression for the base, dihydrogen phosphate?

What is the concentration of the acetate ion in a 1.00 M CH₃COOH solution given that the K_a of CH₃COOH is 1.8  10^⁵?

What is the concentration of [OH^] in a 0.20 M solution of ammonia? The K_b value for ammonia is 1.8  10^⁵.

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

The pH of an ammonia solution is 11.6, and the solution has a concentration of about 0.20 M. The pK_b of ammonia is 4.75. What is the percent ionization of ammonia?

When [H^]  1.0  10^⁷ M in water at 25C, then ________

Which of the following salts produce(s) a basic solution when dissolved in water? NH₄Cl K₂S NaCN CsNO₃

A solution with a pOH of 6.92 has an [OH^] concentration of ________