Lead Acetate Peroxide

Add hydrogen peroxide to the lead sulphate precipitate in a test tube and shake it vigorously. What changes do you observe Write the equation of the reaction. Does lead form sulphosalts Why is lead acetate, and not another salt, used in all the reactions ... 

Lead Peroxide.—100 gms. of bleaching powder are shaken up with 1,500 c.cs. of water and filtered. The filtrate is added gradually to a hot solution of 50 gms. lead acetate in 250 c.cs. of water the addition is continued until the precipitate turns dark brown, and until no precipitate is formed by further addition of bleaching powder solution to a filtered test portion. The liquid is decanted, and the precipitate washed several times with water, then filtered and washed with water. It is preserved in a well-stoppered bottle in the form of a thick paste. 

Lead acetate [134, 482—484], nickel peroxide [445, 485, 486], and some other substances [487 189] are used as oxidants in most cases. 

Chromate, (i) Hydrogen peroxide test (IV.33, 4). (ii) Lead acetate solution test (IV.33,3). (iii) Action of hydrogen sulphide or sulphur dioxide (IV.33, 5,6). 

Lead acetate, carbonate, dioxide (peroxide), nitrate. 

Lead Peruranate, (PbOlg.UOj-i-PbO.UOg, separates as a deep orange-coloured crystalline precipitate when lead acetate is added to a solution of the sodium salt. This compound is not of the usual type, since there is no peroxide oxygen attached to the lead. 

Sulphurj in the unoxidized condition, is tested for by heating the compound with metallic sodium or with sodium carbonate, by which treatment the sulphur is converted into sodium sulphide. If the fused product is placed on a silver coin and moistened, a spot of siVoer sulphide will be produced. The fused mass may also be dissolved in water, neutralized with nitric acid, and a little lead acetate solution added. The formation of a black precipitate of lead sulphide proves the presence of sulphur. These tests are applicable only in case the sulphur is in an unoxidized form. To test for sulphur in either the oxidized or unoxidized form a little of the compound is boiled with strong nitric acid or is heated with sodium peroxide. This treatment converts the sulphur into the form of sulphuric acid or a sulphate, either of which will yield a white precipitate of barium sulphate when tested with barium nitrate in the presence of nitric acid. 

Permanent hair colors contain an oxidizer (usually 6% hydrogen peroxide) and a dye intermediate (p-phenylenediamine, resorcinol, aminophenols along with water, ammonia, glycerin, isopropanol, and propylene glycol). Semipermanent hair colors contain propylene glycol, isopropanol, fatty acids, fragrance, alkanolamines, and dyes. Some Grecian hair formulations contain lead in the form of lead acetate. 

Oxidation reactions also include those reactions that involve the formation of new carbon/oxygen bonds. We have already seen an example the addition of hydrogen peroxide to a carbon/carbon double bond to give the 1,2-diol. Such compounds may undergo further oxidation by treatment with periodic acid, HI04, or lead acetate, Pb(OAc)4. These two reagents are complementary, as the... 

Hydrogen peroxide Lead acetate Lithium carbonate Metal oxides... 

Lead Dioxide. Lead oxide brown lead peroxide lead superoxide. 02Pb mol wt 239.21. O 13.38%, Pb 36.62%. Occurs in nature as the mineral plattnerite. Lab prepn from lead acetate and calcium hypochlorite Newel], Maxson, Inorg. Syn. 1, 45 ( 939) by hydrolysis of lead acetate Kuhn, Hammer, Ber. 83, 413 (1950). 

Geist, C. R. and Mattes, B. R. (1979). Behavioral effects of postnatal lead acetate exposure in developing laboratory rats. Physiol. Psychol., 7, 399 Geist, C. R. and Praed, J. E. (1982). Chronic lead exposure of rats open-field performance. Perceptual Motor Skills, 55, 487 Gelman, B. G. and Michaelson, I. A. (1979). Neonatal lead toxicity and in vitro lipid peroxidation of rat brain. /. Toxicol. Env. Health, 5, 671 Gelman, B. G., Michaelson, I. A. and Bornschein, R. L. (1979). Brain lipofuscin concentration and oxidant defence enzymes in lead-poisoned neonatal rats. J. Toxicol. Env. Health, 5, 683... 

Paramecium caudatum (the wild strain) cell culture was cultivated in the Lozina-Lozinsky medium with addition of nutritive medium yeasts containing Saccharomy-ces cerevisiae yeasts. The oxidative stress was induced by cadmium chloride, lead acetate, and hydrogen peroxide (H O ). Infusorians sensitivity to toxic agents was determined by time of their death established by protozoa motion cessation, often accompanied by cell deformation and cytolysis. The exposure time was 2hours. The control in all tests was the number of cells in 10 ml of the medium containing the intact culture of infusorian (without oxidative stress induction). 

By the 15th day, only an insignificant decrease in the species population was observed, when ascorbic acid or lead acetate was added to the cell culture. Thus, here ascorbic acid manifested similar antioxidant activity as against hydrogen peroxide. 

The stability of hypertensin is maximum between pH 1.5 and 8.5, but as the purification progresses, the stability decreases. Outside of this pH range, the destruction of hypertensive activity increases considerably, especially in alkaline media. Hydrogen peroxide, bromine water, iodine, nitrous acid, hydroxylamine, lead acetate, destroy this activity. 

Glycerol Triacetate 102-76-1 Hydrogen Peroxide 7722-84-1 Lead Acetate 15347-57-6... 

Properly end-capped acetal resins, substantially free of ionic impurities, are relatively thermally stable. However, the methylene groups in the polymer backbone are sites for peroxidation or hydroperoxidation reactions which ultimately lead to scission and depolymerisation. Thus antioxidants (qv), especially hindered phenols, are included in most commercially available acetal resins for optimal thermal oxidative stabiUty. 

Sorbic acid is oxidized rapidly in the presence of molecular oxygen or peroxide compounds. The decomposition products indicate that the double bond farthest from the carboxyl group is oxidized (11). More complete oxidation leads to acetaldehyde, acetic acid, fumaraldehyde, fumaric acid, and polymeric products. Sorbic acid undergoes Diels-Alder reactions with many dienophiles and undergoes self-dimerization, which leads to eight possible isomeric Diels-Alder stmctures (12). 

Chain transfer also occurs to the emulsifying agents, leading to their permanent iacorporation iato the product. Chain transfer to aldehydes, which may be formed as a result of the hydrolysis of the vinyl acetate monomer, tends to lower the molecular weight and slow the polymerisation rate because of the lower activity of the radical that is formed. Thus, the presence of acetaldehyde condensates as a poly(vinyl alcohol) impurity strongly retards polymerisation (91). Some of the initiators such as lauryl peroxide are also chain-transfer agents and lower the molecular weight of the product. 

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