Oxidation-Reduction Reactions and Methods of Analysis

Vocabulary flashcards related to oxidation-reduction reactions and methods of analysis, covering half-equation methods, standard solutions, Faraday's Law, and specific substances assayed by different titration methods.

Half-Equation Method

A method to balance redox reactions by separating them into oxidation and reduction half-reactions.

Oxidation

Loss of electrons.

Reduction

Gain of electrons.

Reducing Agent

Substance that loses electrons and causes another substance to be reduced.

Oxidizing Agent

Substance that gains electrons and causes another substance to be oxidized.

Examples of Oxidizing Agents

Ferric ammonium sulfate, potassium dichromate, potassium bromate, potassium iodate, potassium permanganate, ceric sulfate, iodine, bromine.

Examples of Reducing Agents

Ferrous ammonium sulfate, oxalic acid, potassium arsenite, ascorbic acid, stannous chloride, sodium thiosulfate.

Oxidation-Reduction

Method of analysis involving a change in valence of the reacting substance.

Faraday’s Law

Change in charge of one substance is equivalent to the gain or loss of 96,500 C of electricity per equivalent weight.

KMnO4

Solution of potassium permanganate that retains its concentration and serves as an indicator, utilized to assay reducing agents.

Substances Assayed by Direct Titration with KMnO4

Hydrogen peroxide solution, manganese dioxide, titanium dioxide, cherry juice (malic acid).

Iodimetry

Assay of reducing agents involving iodine.

Direct titration Iodimetry sample

Ascorbic Acid, tartar emetic.

Residual titration Iodimetry sample

Calomel (mercury chloride), Antipyrine.

Iodometry

Assay of oxidizing agents involving iodide.

Direct titration Iodometry sample

CuSO4; NaOCl (sodium hypochlorite)

Residual titration Iodometry sample

Phenol, Resorcinol, PbO

Indicators for Iodometry & Iodimetry

Starch TS: iodi – colorless, iodo – blue; Chloroform, CCl4.

Cerimetry

Assay using cerium sulfate.

Cerimetry Samples

Vitamin K. (menadione), FeSO4

Indicator for Cerimetry

Orthophenanthroline, Ts (Red to blue).

Ceric Sulfate

Solution of ceric sulfate in diluted sulfuric acid, a strong oxidizing agent that is more stable than standard permanganate solutions.