Phenols in water

Dissolve a few crystals of phenol in water and add ferric chloride solution a violet coloration is produced. Repeat, using i 2 drops of m-cresol shaken up with about i ml. of water a violet coloration is again produced. Catechol (in dilute solution) gives a green coloration. 

Phenols. The first stable ozone oxidation product of phenol in water is ds ds-raucomc acid, which requires - 2 mol O /mol phenol. In practice, larger dosage levels of ozone are required because other ozone-reactive substances are present in most wastes. Ozone oxidation of phenoHc effluents is employed in paper mills, coke mills, oil refineries, and thermoplastic resin manufacture, producing effluents that are safe to freshwater biota (122,123) (see Lignin Pulp). 

The aromatic ring of alkylphenols imparts an acidic character to the hydroxyl group the piC of unhindered alkylphenols is 10—11 (2). Alkylphenols unsubstituted in the ortho position dissolve in aqueous caustic. As the carbon number of the alkyl chain increases, the solubihty of the alkah phenolate salt in water decreases, but aqueous caustic extractions of alkylphenols from an organic solution can be accomphshed at elevated temperatures. Bulky ortho substituents reduce the solubihty of the alkah phenolate in water. The term cryptophenol has been used to describe this phenomenon. A 35% solution of potassium hydroxide in methanol (Qaisen s alkah) dissolves such hindered phenols (3). 

Reactions.—I. Make a solution of phenol in water, and to one portion add a drop of ferric chloride. A violet colouration is produced. 

Fe7-ric chloride reaclion.—Dissolve a drop of the free phenol in water and add a drop of ueutral ferric chloride. A green (catechol), blue (orcinol, pyiogallol) or purple (phenol, resorcinol) colouration is produced, which is often destroyed by acid or alkali. Quinol is o.xidised to quinone, and turns biown (p. 193). The naphthols give precipitates of dinaphthol (p. 220). 

Behavior of a-sulfinyl and a-sulfonyl carbanions TABLE 3. pK, values of substituted phenols in water at 25 °C... 

Phenol (C5H5OH) or carboUc acid is an aromatic hydrocarbon derived originally from coal tar, but prepared synthetically in a process that utilizes monochlorobenzene as a starting point. Ninety-eight percent phenol appears as transparent crystals, while liquefied phenol consists of 88% USP solution of phenol in water. 

Chlorinated dibenzo ip-dioxins are contaminants of phenol-based pesticides and may enter the environment where they are subject to the action of sunlight. Rate measurements showed that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is more rapidly photolyzed in methanol than octachlorodi-benzo-p-dioxin. Initially TCDD yields 2,3,7-trichlorodiben-zo-p-dioxin, and subsequent reductive dechlorination is accompanied by ring fission. Pure dibenzo-p-dioxin gave polymeric material and some 2,2 -dihydroxybiphenyl on irradiation. Riboflavin-sensitized photolysis of the potential precursors of dioxins, 2,4-dichlorophenol and 2,4,5-trichloro-phenol, in water gave no detectable dioxins. The products identified were chlorinated phenoxyphenols and dihydroxy-biphenyls. In contrast, aqueous alkaline solutions of purified pentachlorophenol gave traces of octachlorodibenzo-p-dioxin on irradiation. 

Matthews RW, McEvoy SR (1992) Destruction of phenol in water with sun, sand and photocatalysis. Sol Energy 49(6) 507-513... 

Li J, Sato M, Ohshima T (2007) Degradation of phenol in water using a gas-liquid phase pulsed discharge plasma reactor. Thin Solid Films 515 4283-4288... 

Entezari MH, Petrier C, Devidal P (2003) Sonochemical degradation of phenol in water a comparison of classical equipment with a new cylindrical reactor. Ultrason Sonochem 10 103-108... 

Navarro A, Lacorte S, Barcelo D (2010) Occurrence and transport of pesticides and alkyl-phenols in water samples along the Ebro river basin. J Hydrol 383 18-29... 

Diazotization Diazonium ion decomposition gives a phenol in water and reduction in SDS Abe etal., 1983... 

Table 11 Acid dissociation constants for the phenols in water and methanol, as well as second-order rate constants for the various methanolysis reactions of phosphonates 22a-e promoted by methoxide, La3 + and 9 Zn2 + ( OCH3)...

Phenol in water is relatively reactive, thereby explaining its potency against bacteria. But phenol dissolved in water contains relatively few solvated protons, so it is not particularly acidic. But its old name is carbolic acid ... 

Materials Required Thyroid gland dried 1.0 g anhydrous potassium carbonate 17.0 g bromine solution (9.6 ml of Br2 and 30 g of KBr in 100 ml DW) 7.0 ml dilute phosphoric acid (10% w/v) 42.0 ml starch iodide paper phenol solution (saturated solution of phenol in water) 5.0 ml potassium iodide solution (10% w/v in water) 0.01 N sodium thiosulphate solution starch solution. 

Complexes between amines and phenols in apolar solvents56 were extensively investigated by several techniques. The equilibrium between molecular complexes and ions was recently investigated57 by 1H NMR techniques for the complexes between phenols and /V./V-dirncthylaniline. The constant of the proton transfer equilibrium (K of equilibrium 7) increases on increasing ApKa (= pKa of protonated base —pKa of phenol) in water, and when the solutions are cooled. 

Her Majesty s Stationery Office 1981 Phenols in waters and effluents. 

Phenol is a colorless-to-white solid when pure however, the commercial product, which contains some water, is a liquid. Phenol has a distinct odor that is sickeningly sweet and tarry. Most people begin to smell phenol in air at about 40 parts of phenol per billion parts of air (ppb), and begin to smell phenol in water at about 1-8 parts of phenol per million parts of water (ppm ... 

Phenol can have beneficial effects when used for medical reasons. It is an antiseptic (kills germs) when applied to the skin in small amounts and may have antiseptic properties when gargled as a mouthwash. It is an anesthetic (relieves pain) and is a component of certain sore-throat lozenges and throat sprays or gargles. Small amounts of phenol in water have been injected into nerve tissue to lessen pain associated with certain nerve disorders. Phenol destroys the outer layers of skin if allowed to remain in contact with skin, and small amounts of... 

The EPA lifetime health advisory for phenol in water is 4 mg/L. EPA has determined that the level of phenol in ambient water (lakes, streams) should be limited to 3.5 mg/L in order to protect human health from the potential toxic effects of exposure to phenol through ingestion of water and contaminated aquatic organisms. 

Dyspnea and rales were observed in pregnant rats treated by gavage with phenol in water on gestation days 6-19 (Narotsky and Kavlock 1995). The respiratory effects were observed at both 40 and 53.3 mg/kg/day. Furthermore, developmental toxicity occurred on the litters of 1 of 5 low-dose and 3 of 16 high-dose dams that exhibited these effects, although not all dams with severe respiratory effects had abnormal outcomes. 

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