Providing Supplementary Materials from Chemistry as a Means of Raising Teaching Effectiveness
Providing Supplementary Materials from Chemistry as a Means of Raising Teaching Effectiveness
Avanesova Nelly,
Hovsepyan Anzhela,
Kotsinyan Tatevik
Summary
Key words: quantum of light, aromatic compounds, complex formation, iron(III) chloride, chromophore, conjugated bonds
Qualitative reactions allow the determination of the presence of specific molecules, atoms, and ions in a given sample. These reactions include many well-known tests. The state of the electron system – encompassing the entire molecule – is crucial for the manifestation of a particular color. Moreover, the mechanism of color formation differs between inorganic and organic compounds. This article is devoted to studying the changes in the color of organic compounds, particularly the complex formation processes of phenols and their derivatives with iron (III) chloride. The article presents the basic principles of coloration theory and examines how color changes depend on several factors: the substance’s structure, the presence of chromophoric and auxochromic groups, conjugated bonds, and aromatic rings. The discussed factors influencing the course of complex formation reactions and the color of the resulting complexes demonstrate the dominant role of the chromophoric –OH group in generating the color of the complex. Furthermore, the color of the complex compound also depends on the number of chromophoric groups, their positions within the molecule, and the presence, the number of benzene rings in the analyzed samples.