Question 1

H-A is an acid with a pKa of 4.5. Which of the following statements about an aqueous solution of H-A is true?

Accepted Answer

A) At pH = 4.5, the solution contains much more H-A than A- 
B) At pH = 4.5, the solution contains much more A- than H-A 
C) At pH- 3.5, the solution contains about 90% A- and 10% H-A 
D) At pH = 6.5, the soluton contains about 80% A- and 20% H-A 
E) At pH = 5.5, the solution contains about 90% A- and 10% H-A 
A) At pH = 4.5, the solution contains much more H-A than A- 
B) At pH = 4.5, the solution contains much more A- than H-A 
C) At pH- 3.5, the solution contains about 90% A- and 10% H-A 
D) At pH = 6.5, the soluton contains about 80% A- and 20% H-A 
E) At pH = 5.5, the solution contains about 90% A- and 10% H-A E

Question 2

Which of the following is the strongest acid?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) V 
A) I 
B) II 
C) III 
D) IV 
E) V E

Question 3

The amino acid glycine (H3N+CH2CO2H)has two acidic Hs, one with pKa = 2.34 and the other with pKa=9.60. Draw the structure of the form of glycine that predominates at a pH of 12.

Accepted Answer

Question 4

2-Propanol is shown below. Draw the structure of its conjugate base.
(CH3)2CHOH

Accepted Answer

Question 5

What is the product formed from the following acid-base reaction when ammonia functions as a base? The equilibrium lies far to the reactants.

Accepted Answer

A) CH3O- + +NH4 
B) CH2OH + +NH3 
C) CH3OH2+ + -NH2 
D) CH3NH2 + H2O 
E) CH4 + NH2OH 
A) CH3O- + +NH4 
B) CH2OH + +NH3 
C) CH3OH2+ + -NH2 
D) CH3NH2 + H2O 
E) CH4 + NH2OH

Question 6

Which species act as bases in the following reaction?

Accepted Answer

A) 1 and 2 
B) 3 and 4 
C) 2 and 4 
D) 1 and 3 
E) 2 and 3 
A) 1 and 2 
B) 3 and 4 
C) 2 and 4 
D) 1 and 3 
E) 2 and 3

Question 7

Which of the following anions, CH3CHBrCO2- or CH3CHFCO2- is the stronger base? Explain your choice.

Accepted Answer

CH₃CHBrCO₂^- is the stronger base. The more

Question 8

What is the conjugate acid of CH3NH2?

Accepted Answer

A) CH3NH3+ 
B) CH3NH- 
C) NH4+ 
D) NH2- 
A) CH3NH3+ 
B) CH3NH- 
C) NH4+ 
D) NH2-

Question 9

If H2O has a pKa value of 15.7 and HF has a pKa value of 3.2, which is a stronger base, HO- or F-? Explain.

Accepted Answer

HO^- is a stronger base than F^- b

Question 10

Would you predict trifluoromethanesulfonic acid, CF3SO3H, to be a stronger or weaker acid than methanesulfonic acid, CH3SO3H? Explain your reasoning.

Accepted Answer

Trifluoromethanesulfonic acid is a stron

Question 11

Which of the following is the strongest acid?

Accepted Answer

A) HF 
B) H2O 
C) : NH3 
D) CH4 
E) CH3OH 
A) HF 
B) H2O 
C) : NH3 
D) CH4 
E) CH3OH

Question 12

When a small amount of hexanoic acid [CH3(CH2)4CO2H, pKa~4.8], is added to a separatory funnel which contains the organic solvent diethyl ether and water with a pH of 2.0, it is found mainly in the ________ phase as ________.

Accepted Answer

A) ether; CH3(CH2)4CO2- 
B) water; CH3(CH2)4CO2- 
C) ether; CH3(CH2)4CO2H 
D) water; CH3(CH2)4CO2H 
E) none of the above 
A) ether; CH3(CH2)4CO2- 
B) water; CH3(CH2)4CO2- 
C) ether; CH3(CH2)4CO2H 
D) water; CH3(CH2)4CO2H 
E) none of the above

Question 13

At what pH will 25% of a compound with a pKa of 5.3 be in its basic form?

Accepted Answer

The answer of At what pH will 25% of a...

Question 14

When a small amount of hexanoic acid [CH3(CH2)4CO2H, pKa~4.8], is added to a separatory funnel which contains the organic solvent diethyl ether and water with a pH of 12.0, it is found mainly in the ________ phase as ________.

Accepted Answer

A) ether; CH3(CH2)4CO2- 
B) water; CH3(CH2)4CO2- 
C) ether; CH3(CH2)4CO2H 
D) water; CH3(CH2)4CO2H 
E) none of the above 
A) ether; CH3(CH2)4CO2- 
B) water; CH3(CH2)4CO2- 
C) ether; CH3(CH2)4CO2H 
D) water; CH3(CH2)4CO2H 
E) none of the above

Question 15

The pKa of CH3COOH is 4.8 and the pKa of HCOOH is 3.8. Given this information, one knows that ________.

Accepted Answer

A) CH3COOH completely ionizes in water 
B) HCOOH is a weaker acid than CH3COOH 
C) HCOO- is a weaker base than CH3COO- 
D) CH3COOH reacts with HO- while HCOOH does not 
E) HCOOH reacts with HO- while CH3COOH does not 
A) CH3COOH completely ionizes in water 
B) HCOOH is a weaker acid than CH3COOH 
C) HCOO- is a weaker base than CH3COO- 
D) CH3COOH reacts with HO- while HCOOH does not 
E) HCOOH reacts with HO- while CH3COOH does not

Question 16

At what pH will the concentration of a compound with a pKa of 5.7 be 100 times greater in its acidic form than in its basic form?

Accepted Answer

The answer of At what pH will the concentration of...

Question 17

Which of the following is the strongest acid?

Accepted Answer

A) CH3OH 
B) CH3OH2+ 
C) H2N- 
D) CH3NH2 
E) CH3NH3+ 
A) CH3OH 
B) CH3OH2+ 
C) H2N- 
D) CH3NH2 
E) CH3NH3+

Question 18

Propanoic acid, CH3CH2COOH, has a pKa =4.9. Draw the structure of the conjugate base of propanoic acid and give the pH above which 90% of the compound will be in this conjugate base form.

Accepted Answer

Question 19

Write a completed equation for the acid-base pair shown below.
HCO2H + -NH2 →

Accepted Answer

HCO₂H + ^-NH₂

Question 20

Which of the following is the strongest acid?

Accepted Answer

A) CH3CH2OH 
B) CH3OCH3 
C) CH3-NH-CH3 
D) CH3-C   CH 
E) CH3-CH   CH2 
A) CH3CH2OH 
B) CH3OCH3 
C) CH3-NH-CH3 
D) CH3-C   CH 
E) CH3-CH   CH2

Exam 2: Acids and Bases: Central to Understanding Organic Chemistry

H-A is an acid with a pKa of 4.5. Which of the following statements about an aqueous solution of H-A is true?

Which of the following is the strongest acid?

The amino acid glycine (H3N+CH2CO2H)has two acidic Hs, one with pKa = 2.34 and the other with pKa=9.60. Draw the structure of the form of glycine that predominates at a pH of 12.

2-Propanol is shown below. Draw the structure of its conjugate base. (CH3)2CHOH

What is the product formed from the following acid-base reaction when ammonia functions as a base? The equilibrium lies far to the reactants.

Which species act as bases in the following reaction?

Which of the following anions, CH3CHBrCO2- or CH3CHFCO2- is the stronger base? Explain your choice.

What is the conjugate acid of CH3NH2?

If H2O has a pKa value of 15.7 and HF has a pKa value of 3.2, which is a stronger base, HO- or F-? Explain.

Would you predict trifluoromethanesulfonic acid, CF3SO3H, to be a stronger or weaker acid than methanesulfonic acid, CH3SO3H? Explain your reasoning.

Which of the following is the strongest acid?

When a small amount of hexanoic acid [CH3(CH2)4CO2H, pKa~4.8], is added to a separatory funnel which contains the organic solvent diethyl ether and water with a pH of 2.0, it is found mainly in the ________ phase as ________.

At what pH will 25% of a compound with a pKa of 5.3 be in its basic form?

When a small amount of hexanoic acid [CH3(CH2)4CO2H, pKa~4.8], is added to a separatory funnel which contains the organic solvent diethyl ether and water with a pH of 12.0, it is found mainly in the ________ phase as ________.

The pKa of CH3COOH is 4.8 and the pKa of HCOOH is 3.8. Given this information, one knows that ________.

At what pH will the concentration of a compound with a pKa of 5.7 be 100 times greater in its acidic form than in its basic form?

Which of the following is the strongest acid?

Propanoic acid, CH3CH2COOH, has a pKa =4.9. Draw the structure of the conjugate base of propanoic acid and give the pH above which 90% of the compound will be in this conjugate base form.

Write a completed equation for the acid-base pair shown below. HCO2H + -NH2 →

Which of the following is the strongest acid?

Remembering General Chemistry: Electronic Structure and Bonding

An Introduction to Organic Compounds

Isomers: the Arrangement of Atoms in Space

Alkenes Thermodynamics and Kinetics

Reactions of Alkenes

Reactions of Alkynes Introduction to Multistep Synthesis

Electron Delocalization, Resonance, and Aromaticity More About Molecular Orbital Theory

Substitution Reactions of Alkyl Halides

Elimination Reactions of Alkyl Halides Competition Between Substitution and Elimination

Reactions of Alcohols, Ethers, Epoxides, and Sulfur-Containing Compounds

Organometallic Compounds

Reactions of Alkanes, Radicals

Mass Spectrometry, Infrared Spectroscopy, and Uvvis Spectroscopy

Nmr Spectroscopy

Reactions of Carboxylic Acids and Carboxylic Acid Derivatives

Reactions of Aldehydes and Ketones

Reactions at the Alpha Carbon of Carbonyl Compounds

Reactions of Benzene and Substituted Benzenes

More About Amines Heterocylic Compounds

Carbohydrates

Amino Acids, Peptides, and Proteins

Catalysis

The Organic Mechanisms of the Coenzymes

The Chemistry of Metabolism

Nucleosides, Nucleotides, and Nucleic Acids

Synthetic Polymers

Pericyclic Reactions

Filters

The amino acid glycine (H₃N⁺CH₂CO₂H)has two acidic Hs, one with pKa = 2.34 and the other with pKa=9.60. Draw the structure of the form of glycine that predominates at a pH of 12.

2-Propanol is shown below. Draw the structure of its conjugate base. (CH₃)₂CHOH

Which of the following anions, CH₃CHBrCO₂^-or CH₃CHFCO₂^- is the stronger base? Explain your choice.

What is the conjugate acid of CH₃NH₂?

If H₂O has a pK_a value of 15.7 and HF has a pK_a value of 3.2, which is a stronger base, HO^- or F^-? Explain.

Would you predict trifluoromethanesulfonic acid, CF₃SO₃H, to be a stronger or weaker acid than methanesulfonic acid, CH₃SO₃H? Explain your reasoning.

When a small amount of hexanoic acid [CH₃(CH₂)₄CO₂H, pKa~4.8], is added to a separatory funnel which contains the organic solvent diethyl ether and water with a pH of 2.0, it is found mainly in the phase as .

When a small amount of hexanoic acid [CH₃(CH₂)₄CO₂H, pK_a~4.8], is added to a separatory funnel which contains the organic solvent diethyl ether and water with a pH of 12.0, it is found mainly in the phase as .

The pKa of CH₃COOH is 4.8 and the pKa of HCOOH is 3.8. Given this information, one knows that ________.

Propanoic acid, CH₃CH₂COOH, has a pKa =4.9. Draw the structure of the conjugate base of propanoic acid and give the pH above which 90% of the compound will be in this conjugate base form.

Write a completed equation for the acid-base pair shown below. HCO₂H + ^-NH₂ →