Chemistry Carboxylic Acids DUHS 2022
PMDC Verified Question 47 of 94
\( \text{HOOC} - \text{COOH} \) has IUPAC name
A
Acetic acid
B
Oxalic acid
C
Diethanoic acid
D
Ethandioic acid
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option D: Ethandioic acid
Concept:

The IUPAC nomenclature for dicarboxylic acids dictates finding the longest continuous carbon chain containing both carboxyl groups and appending the suffix "-dioic acid" to the parent alkane name.

Formula:

$$ \text{HOOC}-\text{COOH} $$

Solution:

  • The structure consists of exactly 2 carbon atoms bonded together.


  • The 2-carbon parent alkane is ethane.


  • Because there are two carboxylic acid groups, the suffix is "-dioic acid".


  • Therefore, the official IUPAC name is ethanedioic acid.


Why other options are incorrect:

"Oxalic acid" is the common (trivial) name, not the IUPAC name. Acetic acid (ethanoic acid) is a monocarboxylic acid. "Diethanoic acid" is not valid nomenclature.

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