Photographic developing and

The close electrochemical relationship of the simple quinones, (2) and (3), with hydroquinone (1,4-benzenediol) (4) and catechol (1,2-benzenediol) (5), respectively, has proven useful in ways extending beyond their offering an attractive synthetic route. Photographic developers and dye syntheses often involve (4) or its derivatives (10). Biochemists have found much interest in the interaction of mercaptans and amino acids with various compounds related to (3). The reversible redox couple formed in many such examples and the frequendy observed quinonoid chemistry make it difficult to avoid a discussion of the aromatic reduction products of quinones (see Hydroquinone, resorcinol, and catechol). 

The oxidizing properties of MnOy are utilized in the oxidation of aniline for the preparation of hydroquinone which is important as a photographic developer and also in the production of dyes and paints. 

Uses. In manufacture of dyes, other organic chemicals, wood preservatives, photographic developer, and explosives... 

One of the most prominent uses of hydroquinone is in photographic development and it is possible that work as a photographic processor often involved hydroquinone exposure in the past. Several studies have examined cancer risks among photographic processors. However, the Working Group did not use these except where the report provided some information indicating that the workers concerned had indeed been exposed to hydroquinone. 

The product 24 is a photographic developer and is oxidized either by activated silver bromide or by 23 to a new quinonimmonium salt, 25 ... 

Boyack [114] has used an electrode theory of development to derive characteristic curves of photographic development and its temperature dependence. The conclusions indicate that ... 

PPD is used in a variety of industrial products. Along with its derivatives, it has important antioxidant actions - used in the manufacturing of synthetic and natural rubbers, petroleum products, cellulose ethers and alfalfa meals [2]. PPD also has commercial application as photographic developers and in a variety of antioxidants and is also used in dyeing furs and... 

Introduction. The quinones are intermediate products in the oxidation of the aromatic nucleus. They may be prepared in some cases by the direct oxidation of aromatic hydrocarbons. For example, anthracene, naphthalene, and phenanthrene are oxidized to the corresponding quinones by chromic acid mixtures. Quinones are prepared more conveniently by oxidation of primary aromatic amines, particularly the p-substituted amines. p-Benzoquinone is obtained by the oxidation of aniline, p-toluidine, sulfanilic acid, p-aminophenol, and other similar compounds. Similarly the a-naph-thoquinone is obtained by oxidation of 1,4-aminonaphthol, and /9-naphthoquinone by the oxidation of 1,2-aminonaphthol. In the laboratory, although it is possible to prepare p-benzoquinone by the oxidation of aniline with acid-dichromate mixture, the method is tedious and the yield poor. Since hydroquinone is used extensively as a photographic developer and is made industrially, it is more convenient to prepare quinone by its oxidation. 

Sodium sulfite is an odorless, solid white powder with a salty sulfurous taste that is soluble in water. It is a reducing agent that is used as a food preservative and antioxidant. Its use is prohibited in meats and other sources of vitamin Bj. Sodium sulfite is also used in the treatment of semichemical pulp in the paper industry, in the treatment of water, as a photographic developer, and in textile bleaching (antic-hlor). It has also found historical use in the water treatment field as a dechlorinating agent. 

Other areas where L-ascorbic acid has found uses in industrial processes are, for example, in polymerLsation reactions, in photographic developing and printing, in metal technology, and even in intravaginal contraceptives. Most of these applications involve the use of the reducing properties of L-ascorbic acid in some way. 

The catalytic hydrogenation of nitrobenzene to p-amionophenol (PAP) under phase-transfer conditions is an industrially important process that was first reported in 1940 (1). PAP is an important intermediate which has been used in the production of analgesic drugs, (2) photographic developers and dyes (3). The... 

SAMPLE PROBLEM 18.9 Determining the pH of a Solution of A Problem Sodium acetate (CH3COONa, or NaAc for this problem) has applications in photographic development and textile dyeing. What is the pH of 0.25 M NaAc of acetic acid (HAc) is 1.8X10 ... 

USE Free acid formerly used in manuf of azo dyes- Sodium salt used as photographic developer and for detection of potassium. 

Cresol is used in disinfectants and fumigants, in the manufacture of synthetic resins, in photographic developers and explosives. 

Hazardous Decomp. Prods. Heated to decomp, emits CO, CO2, NOx, ammonia, traces of organic compds. inc. hydrogen cyanide, nitriles, isocyanates, nitrosamines, amines NFPA Health 3, Flammability 4, Reactivity 0 Uses Intermediate in organic synthesis intermediate for water-gel explosives, accelerators, pharmaceuticals, insecticides, N-methylpyrrolidine, methylalkanolamines, surface active agents, fungicides in tanning component of photographic developers and paint removers fuel additive prod, of dyes polymerization inhibitor rocket propellant See also Methylamine... 

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