Question

Which of the following acids is isomeric with phthalic acid

• A. Succinic acid
• B. Salicylic acid
• C. 1, 4-benzene dicarboxylic acid
• D. Methyl benzoic

Answer 1

Answer: (C)

1, 4-benzene dicarboxylic acid

Answer 2

Phthalic acid is the isomer of 1, 4 benzene dicarboxylic acid because both have the same molecular formula but differ in their structure.