Free Carboxylic Acid Derivatives MCQs with Answers
50 Carboxylic Acid Derivatives MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Carboxylic acid derivatives include acid halides, acid anhydrides, esters and amides, formed by replacing the hydroxyl group of a carboxylic acid. Their nomenclature, structures, preparation, hydrolysis and relative reactivity are linked through nucleophilic acyl substitution, which differs from the nucleophilic addition reactions of aldehydes and ketones.
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50 questions · page 2 of 3
- A. CH3 - NH2
- B. O||CH3 - C - NH2
- C. O||CH3 - C - H
- D. CH3 - C ≡ N
Explanation: Option c is correct because it corresponds to the formation of acetamide through the reaction between acetic acid and ammonia, leading to…
Correct answer: O||CH3 - C - H- A. Ethyl amine
- B. Ethyl Nitrile
- C. Ethyl Diazonium Chloride
- D. Ammonium Acetate
Explanation: Carboxylic acids react with ammonia to form ammonium salts which on heating produce acid amides.
Correct answer: Ammonium Acetate- A. Ester
- B. Anhydride
- C. Acid amide
- D. Ether
Explanation: Option c is the correct answer. An ester functional group is characterized by the formula RCOOR', where R and R' are alkyl or aryl groups.
Correct answer: Ester- A. Hydration
- B. Saponification
- C. Hardening
- D. Dehydration
Explanation: Saponification is the reaction of triglycerides (fats and oils) with alkalies (such as sodium hydroxide or potassium hydroxide) to produce…
Correct answer: Saponification- A. HCOOH + SOCl2 -> HCOCI + SO2 + HCI
- B. CH3CH2COOH + 2SOCl -> CH3CH2COCl + SO2 + HCI
- C. CH3CH2COOH + 2SOCl -> CH3CH2COC1 + SO3 + HCI
- D. CH3COOH + SOCl2 -> CH3COCl + SO2 + HCI
Explanation: Thionyl chloride is SOCl2 and it reacts with carboxylic acids to form acyl chlorides.Options B and C do not involve thionyl chloride, it…
Correct answer: CH3COOH + SOCl2 -> CH3COCl + SO2 + HCI- A. Acetic acid + HCl + H3PO4
- B. Acetic acid + PCl5
- C. Acetic acid + PCl3
- D. Acetic acid + Cl2 + H3PO4
Explanation: The reaction of a carboxylic acid with phosphorus trichloride (PCI3) is a standard method for preparing acyl chlorides.
Correct answer: Acetic acid + PCl3- A. Nitrile
- B. Amide
- C. Ammonia
- D. Acid nitrile
Explanation: This is a nucleophilic acyl substitution reaction. The amine acts as a nucleophile and attacks one of the carbonyl carbons of the…
Correct answer: Amide- A. Acid halide
- B. Acid amide
- C. Ester
- D. Acid anhydride
Explanation: The amide ion (NH2) is a very poor leaving group, making amides the least reactive of the common carboxylic acid derivatives.
Correct answer: Acid amide29. Identify B:
- A. Acetic acid
- B. Ethane nitrile
- C. Acetic anhydride
- D. Acetamide
Explanation: Formation of Amide (Reaction with ammonia): Carboxylic acids react with ammonia to form ammonium salts which on heating produce acid…
Correct answer: Acetamide30. When acetic acid reacts with ammonia the attacking nucleophile and the electrophilic center are:
- A. O and carbonyl C
- B. O and Carbonyl O
- C. N and Carbonyl C
- D. N and Carbonyl O
Explanation: In the reaction between acetic acid (CH3COOH) and ammonia (NH3), the nitrogen atom in ammonia acts as the nucleophile, attacking the…
Correct answer: N and Carbonyl C- A. Acid halide
- B. Acid amide
- C. Ester
- D. Acid anhydride
Explanation: The direct reaction of a carboxylic acid with ammonia results in an acid-base reaction, forming an ammonium carboxylate salt.
Correct answer: Acid amide32. Which sequence of groups replace OH of carboxylic acid to halides, esters and amides respectively:
- A. -OH, -X, -NH2
- B. -X, -OR, -NH2
- C. -NH2, -H, -X
- D. -X, -OR, -NO2
Explanation: Carboxylic acid derivatives are formed by replacing the -OH group. Replacing it with a halogen (-X) gives an acid halide.
Correct answer: -X, -OR, -NH2- A. Water
- B. Ether
- C. Acetone
- D. Both 'B' and 'C'
Explanation: It is a colourless liquid with a pungent odour.It is soluble in both ether acetone and acetic acid.
Correct answer: Both 'B' and 'C'- A. Ethyl alcohol
- B. Propyl alcohol
- C. Butyl alcohol
- D. Methyl alcohol
Explanation: Esters are named with the alkyl group from the alcohol first, followed by the name of the carboxylate from the acid.
Correct answer: Ethyl alcohol- A. SO2
- B. Cl
- C. SO3
- D. No nucleophile is formed
Explanation: In the reaction between acetic acid and thionyl chloride, the chloride ion (Cl-) acts as the nucleophile.
Correct answer: Cl36. Carboxylic acid reacts with ammonia to form ammonium salts which on heating produces_______________?
- A. CO2
- B. Alkane
- C. Ester
- D. Acidamide
Explanation: A carboxylic acid first reacts with ammonia to form ammonium carboxylate, RCOO-NH4+, and heating removes water to form the acid amide…
Correct answer: Acidamide- A. 2
- B. 3
- C. 4
- D. 5
Explanation: The explanation for this question will be added soon.
Correct answer: 4- A. Ethane
- B. Ethanoic Acid
- C. Ethanol
- D. Ethyl Ethanoate
Explanation: The explanation for this question will be added soon.
Correct answer: Ethyl Ethanoate- A. Aldehydes and ketone
- B. Alcohols and ketone
- C. Carboxylic acid and alcohols
- D. Carboxylic acid and aldehydes
Explanation: Esterification is the process of combining an organic acid (RCOOH) with an alcohol (ROH) to form an ester (RCOOR) and water; or a chemical…
Correct answer: Carboxylic acid and alcohols- A. Anhydride > Acylchloride > ester
- B. Ester > Anhydride > Acylchloride
- C. Amide > Acylchloride > ester
- D. Acylchloride > Anhydride > ester
Explanation: Acyl chlorides are the most reactive carboxylic acid derivatives. The electronegative chlorine atom pulls electrons toward it in the C-Cl…
Correct answer: Acylchloride > Anhydride > ester