[Antioxidants - no reason for a reassessment]

The oxidation of an organic compound in the presence of air or oxygen is called autoxidation. For example, cumene reacts with oxygen to form hydroperoxide. Autoxidation involves initiation, propagation, and termination steps. Many organic compounds are susceptible to autoxidation—especially ethers in the presence of oxygen, which form hydroperoxides. Even though this reaction is slow, old ether bottles contain small amounts of peroxide, which leads to laboratory explosions during ether...

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...

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...

Oxidation–Reduction Reactions

Mutagenicity and carcinogenicity refer to the ability of drugs to cause genetic defects and induce cancer, respectively. The International Agency for Research on Cancer (IARC) classifies agents into four groups based on their carcinogenic potential. Group 1 agents are known human carcinogens; group 2A agents are probably carcinogenic to humans; group 3 agents lack data to support their role in carcinogenesis; and group 4 includes agents for which data support that they are not likely to be...

In redox reactions, the transfer of electrons occurs between reacting species. Electron transfer is described by a hypothetical number called the oxidation number (or oxidation state). It represents the effective charge of an atom or element, which is assigned using a set of rules.