Homogeneous Acid Catalysis in Ester Hydrolysis

Steps:

• Define catalysis: substance speeds reaction without net consumption.
• Identify type: H+ ions in aqueous solution with ester, so same phase (homogeneous).
• Check options: A wrong (heterogeneous = different phase); B wrong (catalysts unchanged); D wrong (catalysts lower Ea).
• Confirm C: H+ and reactants (ester, water) all in liquid phase.

Why C is correct:

• Homogeneous catalysts are in the same phase as reactants, per catalysis definition; here, H+ dissolves in water with ester.

Why the others are wrong:

• A: H+ is homogeneous, not heterogeneous (different phases like solid catalyst in gas).
• B: Catalysts regenerate, so H+ not used up (appears in products as well).
• D: Catalysts provide alternate pathway, lowering activation energy.

Final answer: C