Skip to main content

Kinetics of Oxidation of Substituted Phenols by Potassium Bromate | Chapter 02 | Theory and Applications of Chemistry Vol. 3

Kinetic methods of analysis are now accepted as standard analytical procedures for several of reactions, especially oxidation types. Though the reaction of phenols and substituted phenols by potassium bromate is well understood as an oxidative type, there was a need to understand and more evidence required against the participation of Br2 in the increasing rate of reaction with increasing acetic acid composition in the bromate oxidation of phenols. Present work explains the strange behaviour on the basis of formation of HBrO3 that is favoured in acidic medium.

Kinetics of oxidation of 3, 4-Dimethyl phenol, 4-sec-butyl phenol and 4-tert-butyl phenol in aqueous acetic acid - water medium in the temperature range of 308K to 321K were investigated. The reaction obeys first order kinetics with respect to [oxidant], [substrate] and [H+]. The active oxidising species was found to be HBrO3. A suitable mechanism in conformity with the kinetic observation has been proposed. Various activation parameters such as energy of activation (58.59, 61, 43, 65.38 KJ/mol), enthalpy change [56.03, 58.87, 62.82 KJ/mol], free energy change (73.19, 77.17, 77.82 KJ/mol) and entropy of activation (-55.7, -59.45 and -48.78 J/mol/deg) for 3: 4-dimethyl phenol, 4-sec-butyl phenol, 4-tert-butyl phenol at 308K, were obtained. A rate law has been derived on the basis of the data. The order of reactivity among the methyl substituted phenols is 3, 4-dimethyl phenol > p-cresol > phenol. The order of reactivity among higher alkyl substituted phenols is 4-tert-butyl phenol 4-sec-butyl phenol > 4-ethyl phenol >phenol.

Author(s) Details

Dr. Asha Mathew
Department of Chemistry, S.I.W.S. College, Wadala, Mumbai 400031, India.

View Volume:


Popular posts from this blog

Consensus Summit: Lipids and Cardiovascular Health in the Nigerian Population | Chapter 09 | Current Trends in Food Science Vol. 1

Aims: To issue a consensus statement on Lipids and Cardiovascular Health and the impact of their interrelationship in Nigerian Population. Study Design: Experts from a range of relevant disciplines, deliberated on different aspects of Lipids and Cardiovascular Health in the Nigerian Population at a Summit. Place and Duration of Study: The Summit was held in April 2016 at the Nigerian Institute of Medical Research. Methodology: Presentations were made on central themes after which expert participants split into four different groups to consider the questions relevant to different sub themes of the title. Consensus was arrived at, from presentations of groups at plenary. Conclusion: With the increase in the prevalence of NCDs, especially Cardiovascular Disease in Nigeria, and the documented evidence of deleterious effects of lipids, the expert panel called for an urgent need to advocate for the general public and health professionals to make heart-friendly

A Review on Gongronema latifolium, an Extremely Useful Plant with Great Prospects | Chapter 11 | Recent Advances in Biological Research Vol. 3

Gongronema latifolium is a plant that has a wide range of nutritional and ethnomedical uses in different tropical African communities. Scientific reports on the chemical composition and bioactivity (anti-inflammatory, antimicrobial, antidiabetic, antioxidant, anticancer and allelopathic properties) of the plant material by different authors are discussed in this review. Future prospects of the plant extracts in the areas of herbal formulations, food preservation, alcoholic fermentation and beer production, drug discovery and allelopathy are also highlighted. Author   Details: Olugbenga Morebise Faculty of Basic Medical Sciences, All Saints University School of Medicine, Roseau, Commonwealth of Dominica. Read full article: View Volume:

An Overview of Ultrasonic Technology and Its Applications in Food Processing, Preservation and Quality Control | Chapter 03 | Current Research in Science and Technology Vol. 3

Ultrasound is one of the emerging technologies that were developed to minimize processing, maximize quality and ensure the safety of food products. In recent years, ultrasound technology has been used as an alternative processing option to conventional thermal approaches. Although Ultrasonication methods have been used for years in research and diagnostics, major advances have been made in the last decade. The applications for which high power ultrasound can be used range from existing processes that are enhanced by the retrofitting of high power ultrasonic technology, to the development of processes up to now not possible with conventional energy sources. The present paper reviews the generation, principle mechanism, properties, process parameters, applications, merits and demerits and future trends of the ultrasound technology in the food processing. Author(s) Details Er. Bogala Madhu Department of Processing and Food Engineering, College of Technology and Engineering, MP