Moderate

Which one of the following is also known as lactic acid ?

Correct answer: B. 2-Hydroxy propanoic acid

  • A. 3-Hydroxy propanoic acid
  • B. 2-Hydroxy propanoic acid
  • C. 2-hydroxy butanoic acid
  • D. 3-hydroxy butanoic acid

Explanation

Lactic acid has the structure CH3-CH(OH)-COOH, so its systematic name is 2-hydroxypropanoic acid. The hydroxyl group is attached to carbon 2 when numbering begins at the carboxyl carbon. Students commonly choose 3-hydroxypropanoic acid by numbering from the opposite end, but carboxylic acid carbon must receive number 1.

Last updated

About Reactivity of Carboxylic Acids

Carboxylic acids show acidic behaviour because their carboxylate ions are resonance-stabilised, and electron-withdrawing groups can change their strength. Reactions include neutralisation, esterification, formation of acid chlorides and amides, reduction, decarboxylation and substitution at the acyl carbon, which differs from the reactions of phenols.

Practise Carboxylic Acids

550 free Carboxylic Acids MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.

Exams that ask Chemistry questions like this

Chemistry is on 12 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.

Related questions