Unraveling Acid?Base Contributions in P-Nitrophenyl Acetate Hydrolysis: Kinetics, Mechanism, And Activation Parameters in Aqueous Media
Abstract
Hydrolysis of p-nitrophenyl acetate (PNPA) serves as a classical model for studying acid?base catalysis in aqueous solution. Despite its widespread use in enzymology and mechanistic chemistry, comprehensive datasets unifying acid- and base-catalyzed pathways remain limited. In this study, PNPA hydrolysis was monitored spectrophotometrically across pH 2?11 and temperatures 20?45 ?C. Pseudo-first-order rate constants (kobs) were determined from exponential fits of absorbance?time traces at 400 nm. A characteristic U-shaped pH?rate profile was obtained, confirming contributions from both acid- and base-catalyzed pathways. Arrhenius and Eyring analyses yielded an activation energy (E?) of 54.7 kJ?mol??, enthalpy of activation (?H) of 52.2 kJ?mol??, and entropy of activation (?S) of ?47.8 J?mol???K??, consistent with a bimolecular, ordered transition state. The results bridge existing gaps by integrating acid- and base-mediated hydrolysis within a single mechanistic framework, providing a reference dataset for both physical organic chemistry and enzymatic catalysis.
Keywords
PNPA, Ester Hydrolysis, Acid?Base Catalysis, Activation Parameters, Aqueous Kinetics
Citations
IRE Journals:
Ghali Muhammad Rabiu, Musa Hamisu, Ladi Lawan, Mohammed Hussaini, Abba Haruna Adamu "Unraveling Acid?Base Contributions in P-Nitrophenyl Acetate Hydrolysis: Kinetics, Mechanism, And Activation Parameters in Aqueous Media" Iconic Research And Engineering Journals Volume 9 Issue 3 2025 Page 1117-1120 https://doi.org/10.64388/IREV9I3-1710748-3992
IEEE:
Ghali Muhammad Rabiu, Musa Hamisu, Ladi Lawan, Mohammed Hussaini, Abba Haruna Adamu
"Unraveling Acid?Base Contributions in P-Nitrophenyl Acetate Hydrolysis: Kinetics, Mechanism, And Activation Parameters in Aqueous Media" Iconic Research And Engineering Journals, 9(3) https://doi.org/10.64388/IREV9I3-1710748-3992
About IRE Journals
IRE Journals is an open access online journals established with an aim to publish high quality of research work in various diciplines. We have more than 6 years in publications. Over 2500+ papers already published.
Important Links
For Authors
Volume 8:
Issue 1, Issue 2, Issue 3, Issue 4, Issue 5, Issue 6, Issue 7, Issue 8, Issue 9, Issue 10, Issue 11, Issue 12Volume 7:
Issue 1, Issue 2, Issue 3, Issue 4, Issue 5, Issue 6, Issue 7, Issue 8, Issue 9, Issue 10, Issue 11, Issue 12Volume 6:
Issue 1, Issue 2, Issue 3, Issue 4, Issue 5, Issue 6, Issue 7, Issue 8, Issue 9, Issue 10, Issue 11, Issue 12Volume 5:
Issue 1, Issue 2, Issue 3, Issue 4, Issue 5, Issue 6, Issue 7, Issue 8, Issue 9, Issue 10, Issue 11, Issue 12Volume 4:
Issue 1, Issue 2, Issue 3, Issue 4, Issue 5, Issue 6, Issue 7, Issue 8, Issue 9, Issue 10, Issue 11, Issue 12Volume 3:
Issue 1, Issue 2, Issue 3, Issue 4, Issue 5, Issue 6, Issue 7, Issue 8, Issue 9, Issue 10, Issue 11, Issue 12