pKₐ₁ of fumaric acid is more than maleic acid.

Because

Conjugate base of fumaric acid is stabilized by intramolecular H-bonding.

• A. Statement-I is True. Statement-II is a correct explanation for Statement-I
• B. Statement-I is True. Statement-II is true; Statement-II is NOT a correct explanation for Statement-I
• C. Statement-I is True, Statement-II is False.
• D. Statement-I is False. Statement-II is True.

To analyze the statements regarding fumaric acid and maleic acid, let's break down the information provided.

Understanding the Acids

Fumaric acid and maleic acid are both unsaturated dicarboxylic acids, but they differ in their structures and properties.

Statement Analysis

• Statement-I: pKₐ₁ of fumaric acid is more than that of maleic acid. This is true because fumaric acid has a higher pKₐ₁, indicating it is a weaker acid compared to maleic acid.
• Statement-II: The conjugate base of fumaric acid is stabilized by intramolecular hydrogen bonding. This is also true, as the structure of fumaric acid allows for such stabilization.

Evaluating the Relationship

Since both statements are true and Statement-II correctly explains why Statement-I is true, the correct answer is:

A. Statement-I is True. Statement-II is a correct explanation for Statement-I.