Abstract
The kinetics of ethanolamine oxidation by acidified KMnO4 was investigated in the absence and presence of sodium dodecyl sulfate (SDS) was investigated using a pseudo-first-order kinetics approach, with [ethanolamine]o >> [KMnO4]o. The measurements were conducted at λmax = 525 nm using an ultraviolet/visible-1800 Shimadzu spectrophotometer. The stoichiometry showed that 2 moles of KMnO4 were consumed by 5 moles of ethanolamine in the aqueous medium. The reaction orders in both the aqueous and micellar media remained the same with a first-order dependence on [KMnO4] and [ethanolamine] and a fractional-order dependence on [H+]. The dependence on [H+] was in the form of kobs = a + b[H+], and the Michaelis-Menten plot showed the existence of an intermediate complex. The Fourier-transform infrared spectrum suggested the conversion of the OH group in ethanolamine to aldehyde. Activation parameters were obtained from the Arrhenius and Eyring equations as follows: ∆H# = 22.12 kJ mol-1, ∆S# = -0.224 kJ K-1 mol-1, and ∆G# = 88.87 kJ mol-1 in the aqueous medium, and ∆H# = 26.38 kJ mol-1, ∆S# = -0.191 kJ K-1 mol−1, and ∆G# = 83.298 kJ mol-1 in the micellar medium. The similarity in ∆G# values in both media suggests the occurrence of the same reaction mechanism, and the negative ∆S# suggests a rigid transition state and association mechanism. The polymerization test revealed the absence of free radicals, indicating that one-electron oxidation leading to the formation of free radicals could be ruled out. Additionally, Menger–Portnoy’s and Piszkiewicz’s cooperativity models were employed to analyze the micellar effect.
Recommended Citation
Latona, Dayo
(2023)
"Oxidation of Ethanolamine by Potassium Permanganate in the Presence and Absence of Sodium Dodecyl Sulphate: A Kinetic Study in an Acidic Medium,"
Makara Journal of Science: Vol. 27:
Iss.
4, Article 6.
DOI: 10.7454/mss.v27i4.1415
Available at:
https://scholarhub.ui.ac.id/science/vol27/iss4/6
