Question 1

Identify the most acidic carboxylic acid.

Accepted Answer

The acidity of carboxylic acids is influenced by the electron-withdrawing ability of substituents attached to the carbon atom nearest to the carboxyl group. Among the given options, fluorine (F) is the most electronegative element, which means it has the strongest electron-withdrawing effect. This increases the acidity of the carboxylic acid by stabilizing the negative charge on the oxygen atom in the carboxylate ion that forms when the acid donates a proton (H+). Therefore, the carboxylic acid with a fluorine substituent (FCH2COOH) is the most acidic.

Question 2

Predict the direction of equilibrium in the following reaction.Explain your answer.

Accepted Answer

The answer of Predict the direction of equilibrium in the...

Question 3

Explain why AlCl₃ is a Lewis acid.

Accepted Answer

The answer of Explain why AlCl₃ is a Lewis acid....

Question 4

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

At a pH of pKa + 1 (5.5 in this case), the solution will be approximately 90% conjugate base (A^-) and 10% acid (H-A). This is due to the fact that at the pKa of an acid, the concentrations of acid and conjugate base are equal, and for every pH unit above the pKa, the ratio of conjugate base to acid will increase by a factor of 10.

Question 5

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

Accepted Answer

The answer of Would you predict trifluoromethanesulfonic acid,CF₃SO₃H,to be a...

Question 6

Buffering is used to maintain the pH of human blood in the relatively narrow 7.3 - 7.4 range.What acid/base pair serves to buffer the blood?

Accepted Answer

The correct acid/base pair that serves to buffer the blood is carbonic acid (H2CO3) and bicarbonate (HCO3^-), which corresponds to choice C. This system works by the reversible reaction H2CO3 ↔ HCO3^- + H+, allowing the blood to resist changes in pH.

Question 7

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

The answer of Propanoic acid,CH₃CH₂COOH,has a pKa =4.9.Draw the structure...

Question 8

Structure of Lorazepam,a widely known drug for short-term anxiety is shown below.Is the indicated lone pair localized or delocalized?

Accepted Answer

The answer of Structure of Lorazepam,a widely known drug for...

Question 9

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

At a pH of 2.0, which is lower than the pKa of hexanoic acid (4.8), the acid will remain in its protonated form (CH3(CH2)4COOH). In this form, it is less soluble in water and more soluble in organic solvents like diethyl ether. Therefore, it will be found mainly in the ether phase.

Question 10

HCN has a pKa = 9.1.What form of the compound,HCN or CN^-,will predominate in a solution of pH = 7.0

Accepted Answer

The answer of HCN has a pKa = 9.1.What form...

Question 11

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

The answer of The amino acid glycine (H₃N⁺CH₂CO₂H)has two acidic...

Question 12

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 ________.

Accepted Answer

At a pH of 12.0, which is significantly higher than the pKa of hexanoic acid (~4.8), the acid will be deprotonated to form its conjugate base, making it more soluble in water. Therefore, it will be found mainly in the water phase as its deprotonated form.

Question 13

Draw a resonance contributor and the resonance hybrid for HOCO₂^-.

Accepted Answer

The answer of Draw a resonance contributor and the resonance...

Question 14

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 15

The pKa of CH₃COOH is 4.8.If the pH of an aqueous solution of CH₃COOH and CH₃COO^- is 4.8,then one knows

Accepted Answer

At pH 4.8, the solution is at the same pH as the pKa of CH₃COOH, which means that half the CH₃COOH molecules will be in the ionized form (CH₃COO-) and half will be in the unionized form (CH₃COOH). However, since the solution contains both CH₃COOH and its conjugate base CH₃COO^-, the concentrations of each must be equal at equilibrium. Therefore, [CH₃COOH] = [CH₃COO^-] and the correct choice is C.

Question 16

Which of the following is the strongest acid?

Accepted Answer

The answer of Which of the following is the strongest...

Question 17

Explain why : NF₃ is a weaker base than : NH₃.

Accepted Answer

The answer of Explain why : NF₃ is a weaker...

Question 18

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

Accepted Answer

The answer of Which of the following anions,CH₃CHBrCO₂^-or CH₃CHFCO₂^-...

Question 19

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 20

What would be the conjugate base in the following acid base reaction?

Accepted Answer

The answer of What would be the conjugate base in...

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

Identify the most acidic carboxylic acid.

Predict the direction of equilibrium in the following reaction.Explain your answer.

Explain why AlCl₃ is a Lewis acid.

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?

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

Buffering is used to maintain the pH of human blood in the relatively narrow 7.3 - 7.4 range.What acid/base pair serves to buffer the blood?

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.

Structure of Lorazepam,a widely known drug for short-term anxiety is shown below.Is the indicated lone pair localized or delocalized?

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 .

HCN has a pKa = 9.1.What form of the compound,HCN or CN^-,will predominate in a solution of pH = 7.0

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.

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 .

Draw a resonance contributor and the resonance hybrid for HOCO₂^-.

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

The pKa of CH₃COOH is 4.8.If the pH of an aqueous solution of CH₃COOH and CH₃COO^- is 4.8,then one knows

Which of the following is the strongest acid?

Explain why : NF₃ is a weaker base than : NH₃.

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

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?

What would be the conjugate base in the following acid base reaction?

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

Identify the most acidic carboxylic acid.

Predict the direction of equilibrium in the following reaction.Explain your answer.

Explain why AlCl3 is a Lewis acid.

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?

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

Buffering is used to maintain the pH of human blood in the relatively narrow 7.3 - 7.4 range.What acid/base pair serves to buffer the blood?

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.

Structure of Lorazepam,a widely known drug for short-term anxiety is shown below.Is the indicated lone pair localized or delocalized?

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 ________.

HCN has a pKa = 9.1.What form of the compound,HCN or CN-,will predominate in a solution of pH = 7.0

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.

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 ________.

Draw a resonance contributor and the resonance hybrid for HOCO2-.

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

The pKa of CH3COOH is 4.8.If the pH of an aqueous solution of CH3COOH and CH3COO- is 4.8,then one knows

Which of the following is the strongest acid?

Explain why : NF3 is a weaker base than : NH3.

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

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?

What would be the conjugate base in the following acid base reaction?

Explain why AlCl₃ is a Lewis acid.

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

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.

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 .

HCN has a pKa = 9.1.What form of the compound,HCN or CN^-,will predominate in a solution of pH = 7.0

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.

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 .

Draw a resonance contributor and the resonance hybrid for HOCO₂^-.

The pKa of CH₃COOH is 4.8.If the pH of an aqueous solution of CH₃COOH and CH₃COO^- is 4.8,then one knows

Explain why : NF₃ is a weaker base than : NH₃.

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