Question

Maleic acid is stronger than fumaric acid because ?

• A. Fumaric acids shows intermolecular H-bonding
• B. Fumaric acids shows intermolecular ionic bonding
• C. Meleic acid is disasic acid
• D. Meleic acid shows chelation or intramolecular H-bonding

Answer 1

Answer: (A), (D)

The correct options are
A Fumaric acids shows intermolecular H-bonding
D Meleic acid shows chelation or intramolecular H-bonding

Maleic acid, being a cis-isomer is capable of forming intra-hydrogen bond after losing $H^{+}$ ion, making the conjugate base much stable than the trans form (fumaric acid) because both the oxygen atoms have strong interaction with the remaining $H$-atom.

(Refer to Image)

Hence, Aand D are the correct options.