Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Oxidation of Phenols to Quinones

Oxidation of Phenols to Quinones

In the presence of oxidizing agents, phenols are oxidized to quinones. Quinones can be easily reduced back to phenols using mild reducing agents. The electron-donating hydroxyl group enhances the reactivity of the aromatic ring, enabling oxidation of the ring even in the absence of an α hydrogen.
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...

Redox Titration: Overview

Redox Titration: Overview

Redox titration is a chemical analysis technique used to determine the concentration of an unknown substance by measuring the electron transfer in a redox (reduction-oxidation) reaction. The process involves gradually adding a titrant with a known concentration of an oxidizing or reducing agent, to the analyte, the solution with an unknown concentration, until reaching the endpoint, which indicates the completion of the reaction between the two substances. Ensuring the analyte is in a single...

Redox Titration: Other Oxidizing and Reducing Agents

Redox Titration: Other Oxidizing and Reducing Agents

Besides iodine, other oxidizing or reducing agents can serve as titrants in redox titrations. Common oxidizing titrants include KMnO4, cerium(IV), and K2Cr2O7. The choice of oxidizing titrants depends on factors like stability, cost, analyte strength, and reaction rate between the analyte and titrant. KMnO4 is a strong oxidizing titrant that reduces from Mn(VII) to Mn(II) in a highly acidic solution, simultaneously oxidizing the analyte to a higher oxidation state. In this case, KMnO4 acts as a...

Redox Reactions

Redox Reactions

Oxidation-reduction or redox reactions involve the transfer of electrons from one molecule or atom to another. When an atom gains an electron, another atom must lose an electron, meaning oxidation and reduction must occur together. Since the redox occurs in pairs, the atom that gets oxidized is also called the reducing agent or reductant, and the atom that is reduced is also called the oxidizing agent or oxidant. A straightforward way to remember the definitions of oxidation and reduction is...

Indicators

Indicators

Certain organic substances change color in dilute solution when the hydronium ion concentration reaches a particular value. For example, phenolphthalein is a colorless substance in any aqueous solution with a hydronium ion concentration greater than 5.0 × 10−9 M (pH < 8.3). In more basic solutions where the hydronium ion concentration is less than 5.0 × 10−9 M (pH > 8.3), it is red or pink. Substances such as phenolphthalein, which can be used to determine the pH of a solution, are called...

Redox Titration: Iodimetry and Iodometry

Redox Titration: Iodimetry and Iodometry

Iodometry and iodimetry are analytical methods used to determine the concentration of oxidizing or reducing agents using iodine. In iodometric titrations, the oxidizing analyte solution is usually acidified and treated with an excess of iodide ions, which generates an equivalent amount of iodine in equilibrium with triiodide. The released iodine is subsequently titrated directly against a standardized reducing agent. As the dilute iodine color becomes pale yellow, a few drops of freshly...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Global distribution of fungal rhinosinusitis.

Rhinology·2026

Same author

Prevalence of Cryptococcal Antigenemia Among Human Immunodeficiency Virus Infection or Acquired Immunodeficiency Syndrome Patients Attending the Retroviral Clinic in University of Maiduguri Teaching Hospital.

Nigerian journal of clinical practice·2025

Same author

A new family of ant-associated fungi in <i>Chaetothyriales</i>.

Studies in mycology·2025

Same author

Detection of spatiotemporal patterns of rainfall trends, using non-parametric statistical techniques, in Karnataka state, India.

Environmental monitoring and assessment·2023

Same author

Triple-negative Breast Cancer (TNBC) and Its Luminal Androgen Receptor (LAR) Subtype: A Clinicopathologic Review of Cases in a University Hospital in Northwestern Nigeria.

Nigerian journal of clinical practice·2022

Same author

Regional Differences in Antifungal Susceptibility of the Prevalent Dermatophyte Trichophyton rubrum.

Mycopathologia·2020

Search research articles

Related Experiment Video

Updated: Jun 28, 2026

EPR Monitored Redox Titration of the Cofactors of Saccharomyces cerevisiae Nar1

EPR Monitored Redox Titration of the Cofactors of Saccharomyces cerevisiae Nar1

Published on: November 26, 2014

N-substituted phenothiazines as redox indicators in bromatometry.

H S Gowda¹, S A Ahmed

¹Department of Post-graduate Studies and Research in Chemistry, University of Mysore, Manasa Gangotri, Mysore, India.

|March 1, 1979

Summary

Phenothiazine derivatives like diethazine hydrochloride serve as sharp indicators in bromate titrations for estimating quinol and metol. This study details a simple, accurate method using these compounds for quantitative analysis.

More Related Videos

Monitoring the Reductive and Oxidative Half-Reactions of a Flavin-Dependent Monooxygenase using Stopped-Flow Spectrophotometry

Monitoring the Reductive and Oxidative Half-Reactions of a Flavin-Dependent Monooxygenase using Stopped-Flow Spectrophotometry

Published on: March 18, 2012

Measuring Trans-Plasma Membrane Electron Transport by C2C12 Myotubes

Measuring Trans-Plasma Membrane Electron Transport by C2C12 Myotubes

Published on: May 4, 2018

Related Experiment Videos

Last Updated: Jun 28, 2026

EPR Monitored Redox Titration of the Cofactors of Saccharomyces cerevisiae Nar1

EPR Monitored Redox Titration of the Cofactors of Saccharomyces cerevisiae Nar1

Published on: November 26, 2014

Monitoring the Reductive and Oxidative Half-Reactions of a Flavin-Dependent Monooxygenase using Stopped-Flow Spectrophotometry

Monitoring the Reductive and Oxidative Half-Reactions of a Flavin-Dependent Monooxygenase using Stopped-Flow Spectrophotometry

Published on: March 18, 2012

Measuring Trans-Plasma Membrane Electron Transport by C2C12 Myotubes

Measuring Trans-Plasma Membrane Electron Transport by C2C12 Myotubes

Published on: May 4, 2018

Area of Science:

Analytical Chemistry
Organic Chemistry

Background:

Phenothiazine derivatives are widely used in pharmaceuticals.
Titration methods require precise indicators for accurate results.

Purpose of the Study:

To evaluate phenothiazine derivatives as indicators in bromate titrations.
To develop a simple and accurate method for estimating quinol and metol.

Main Methods:

Studied six phenothiazine derivatives: diethazine hydrochloride, butaperazine dimaleate, trifluoperazine hydrochloride, promethazine hydrochloride, prochlorperazine maleate, and chlorpromazine hydrochloride.
Utilized bromate titration for the quantitative analysis of quinol, metol, and ascorbic acid.
Determined the formal potentials of the studied indicators.

Main Results:

All six studied phenothiazine derivatives exhibited sharp, reversible color changes at the equivalence point.
The formal potentials of these indicators were successfully determined.
A straightforward and accurate method for the estimation of quinol and metol was established.

Conclusions:

Phenothiazine derivatives are effective indicators for bromate titrations.
The developed method offers a simple and accurate approach for quantifying quinol and metol.