Free Carboxylic Acids MCQs with Answers
550 Carboxylic Acids 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 acids are named and studied through the combined effects of the carbonyl and hydroxyl groups, their preparation, acidity and hydrogen bonding. Reactions include neutralisation, esterification, reduction and conversion into acid chlorides, anhydrides, esters and amides, with emphasis on how these derivatives interconvert.
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Read the Carboxylic Acids notesFree MDCAT chapter notes with key terms550 questions · page 5 of 28
- 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 amide84. 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: Acetamide85. 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 amide87. 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. Aliphatic
- B. Carboxylic
- C. Alicyclic
- D. Aromatic
Explanation: When a carboxylic acid group (-COOH) is directly attached to the benzene ring of a molecule, it becomes an aromatic carboxylic acid.
Correct answer: Aromatic- A. oxalic
- B. Aromatic acid
- C. Malonic acid
- D. fumaric
Explanation: While all the options contain a carboxylic acid group (-COOH), only malonic acid accurately reflects the structure and nomenclature of…
Correct answer: Malonic acid- A. Lactic acid
- B. Formic acid
- C. Uric acid
- D. Strong acids
Explanation: The primary culprit behind the painful sting of a red ant bite is formic acid (HCOOH).
Correct answer: Formic acid- A. Acetic acid
- B. Formic acid
- C. Carbonic acid
- D. Benzoic acid
Explanation: The correct acid used in the manufacture of synthetic rubber is acetic acid (option a).
Correct answer: Acetic acid- A. Carboxyl to amino group
- B. Amino to carboxyl group
- C. Amino group only
- D. Carboxyl group only
Explanation: In the formation of a zwitterion, a proton shifts from the carboxylic acid group (-COOH) to the amino group (-NH₂) within the amino acid…
Correct answer: Carboxyl to amino group- A. alkane
- B. alcohols
- C. aldehydes
- D. ketones
Explanation: When a carboxylic acid reacts with HI and phosphorus, it undergoes exhaustive reduction, meaning the carbonyl group (-COOH) is completely…
Correct answer: alkane- A. esterification
- B. neutralization
- C. Hydrolysis
- D. Saponification
Explanation: When a carboxylic acid and an alcohol react in the presence of concentrated sulfuric acid, they undergo a condensation reaction known as…
Correct answer: esterification- A. isobutyl formate
- B. Octyl acetate
- C. Ethyl Butyrate
- D. Amyl lactate
Explanation: Ethyl butyrate, a charming ester with the formula CH₃CH₂CH₂COOCH₂CH₃, is widely recognized for its characteristic orange-like scent.
Correct answer: Ethyl Butyrate- A. Lysine
- B. Aspartic acid
- C. alanine
- D. Glutamic acid
Explanation: Alpha-amino succinic acid" is another way to refer to aspartic acid. This term emphasizes its structure:"Alpha-amino" indicates the amino…
Correct answer: Aspartic acid- A. Fructose
- B. Starch
- C. Cellulose
Explanation: Fructose is a simple sugar and is soluble in water. Starch and cellulose are complex carbohydrates and are not soluble in water.
Correct answer: Fructose- A. Acetic acid
- B. Amino acid
- C. Ethyl alcohol
- D. Rayon
Explanation: Acetic acid is used as a coagulant for latex in the rubber industry. When acetic acid is added to latex, it causes the rubber particles to…
Correct answer: Acetic acid