CHEM10050 : Guiry Lecture 15 - Carboxylic Acids and Esters

What functional group is present in all carboxylic acids?

a) Aldehyde

b) Ketone

c) Carboxyl

d) Hydroxyl

c) Carboxyl

Are carboxylic acids strong or weak acids?

a) Strong

b) Weak

b) Weak

Which of the following is a parent compound of esters and amides?

a) Ketones

b) Aldehydes

c) Carboxylic acids

d) Alcohols

c) Carboxylic acids

What is the name given to the OH group bonded to the carbonyl carbon atom in carboxylic acids?

a) Hydroxyl

b) Carbonyl

c) Carboxyl

d) Ester

c) Carboxyl

How do carboxylic acids form esters?

a) Ester + H+

b) Alcohol + H+

c) Carboxylic Acid + OH-

d) Carboxylic Acid + Alcohol

d) Carboxylic Acid + Alcohol

What is the equilibrium constant expression for the reaction between carboxylic acids and water?

a) Kª = [RCO2-][H+]/[RCO2H]

b) Kª = [H2O]/[RCO2H]

c) Kª = [RCO2H]/[H+]

d) Kª = [RCO2-]/[H+]

a) Kª = [RCO2-][H+]/[RCO2H]

What is the reason for the higher boiling point of carboxylic acids compared to alcohols of similar molecular weights?

a) Carboxylic acids have a larger size

b) Carboxylic acids have a stronger dipole moment

c) Carboxylic acids form hydrogen-bonded pairs

d) Carboxylic acids have a higher vapor pressure

c) Carboxylic acids form hydrogen-bonded pairs

How does solubility of carboxylic acids in water depend on the R group?

a) The larger the R group, the more soluble the carboxylic acid is in water

b) The more polar the R group, the less soluble the carboxylic acid is in water

c) The less polar the R group, the more soluble the carboxylic acid is in water

d) The more polar the R group, the more soluble the carboxylic acid is in water

d) The more polar the R group, the more soluble the carboxylic acid is in water

What is the meaning of the term "carboxyl"?

a) Combination of carbonyl and hydroxyl groups

b) Combination of carbonyl and amide groups

c) Combination of carbonyl and ether groups

d) Combination of carbonyl and ester groups

a) Combination of carbonyl and hydroxyl groups

Do humans have enzymes to break down cellulose?

a) Yes

b) No

b) No

What functional group is present in carboxylic acids?

a) OH group bonded to the carbonyl carbon atom

b) NH2 group bonded to the carbonyl carbon atom

c) CO group bonded to the carbonyl carbon atom

d) CH3 group bonded to the carbonyl carbon atom

a) OH group bonded to the carbonyl carbon atom.

Why are carboxylic acids acidic?

a) Due to the stability of the hydroxyl group

b) Due to the stability of the carbonyl group

c) Due to the stability of the carboxylate anion

d) Due to the stability of the ester group

c) Due to the stability of the carboxylate anion.

What are the stable end products of the oxidation of primary alcohols and aldehydes?

a) Carboxylic acid and water

b) Aldehyde and water

c) Ketone and water

d) Ester and water

a) Carboxylic acid and water.

What is required for the reduction of carboxylic acids?

a) Strong oxidizing agent

b) Strong reducing agent

c) Weak oxidizing agent

d) Weak reducing agent

b) Strong reducing agent.

Which reducing agent is milder than LiAlH4?

a) NaBH4

b) H2SO4

c) H2O2

d) KOH

a) NaBH4.

What product is formed when carboxylic acid reacts with alcohol?

a) Carboxylic acid and water

b) Ester and water

c) Ketone and water

d) Alcohol and water

b) Ester and water.

Which principle explains why excess alcohol favors the formation of esters?

a) Le Chatelier's principle

b) Archimedes' principle

c) Pascal's principle

d) Boyle's law

a) Le Chatelier's principle.

What apparatus is used to remove water during ester formation?

a) Buchner funnel

b) Separatory funnel

c) Dean-Stark apparatus

d) Soxhlet extractor

c) Dean-Stark apparatus.

What is the product of the reaction between acetic acid and ethanol?

a) Ethyl acetate and water

b) Acetic acid and water

c) Ethanol and water

d) Ethyl alcohol and water

a) Ethyl acetate and water.

What is the product of the reaction between benzoic acid and ethanol?

a) Ethyl benzoate and water

b) Benzoic acid and water

c) Ethanol and water

d) Benzyl alcohol and water

a) Ethyl benzoate and water.

What functional group is found in esters?

a) OR

b) OH

c) COOH

d) NH2

a) OR

What is the odour of low molecular weight carboxylic acids and esters?

a) Both have a vile odour

b) Carboxylic acids have a vile odour, while esters have a pleasant fragrance

c) Esters have a vile odour, while carboxylic acids have a pleasant fragrance

d) Both have a pleasant fragrance

b) Carboxylic acids have a vile odour, while esters have a pleasant fragrance

What is aspirin?

a) An alcohol

b) A carboxylic acid

c) An ester

d) A ketone

c) An ester

Can the ester group donate hydrogen bonds?

a) Yes

b) No

b) No

How do the boiling points of esters compare to their parent carboxylic acids?

a) Esters have higher boiling points

b) Esters have lower boiling points

c) Esters have the same boiling points

d) Boiling points of esters and carboxylic acids cannot be compared

b) Esters have lower boiling points

Are low molecular weight esters soluble in water?

a) Yes

b) No

a) Yes

What is the general formula of esters?

a) R-O-R

b) R-C-O-H

c) R-C-O-R

d) R-OH

c) R-C-O-R

Are higher molecular weight esters, such as triacylglycerols, soluble in water?

a) Yes

b) No

b) No

In animal fats, is the acyl unit saturated or unsaturated?

a) Saturated

b) Unsaturated

a) Saturated

In vegetable oils, is the acyl unit saturated or unsaturated?

a) Saturated

b) Unsaturated

b) Unsaturated

What reaction forms esters?

a) Reduction

b) Oxidation

c) Hydrolysis

d) Condensation

Answer: d) Condensation