Sodium peroxide, decomposition

PERSULFATE de SODIUM (French) (7775-27-2) Noncombustible, but many chemical reactions cause fire and explosions. Reacts slowly with air, forming sodium dioxide and sodium peroxide. Decomposition at elevated temperatures above 212°F/100°C, emitting oxygen. A strong oxidizer reacts violently with reducing agents, combustible materials, organic substances, powdered metals. Reacts with acrolein, antimony trisulfide, antimony tritelluride, arsenic pentasulfide, 1,1-dichloro-l-nitroethane, 1,3-dichloropropene, diethylamine, -trioxane. Incompatible with m-bis(trichlormethyl)benzene. 

A number of chemiluminescent reactions may proceed through unstable dioxetane intermediates (12,43). For example, the classical chemiluminescent reactions of lophine [484-47-9] (18), lucigenin [2315-97-7] (20), and transannular peroxide decomposition. Classical chemiluminescence from lophine (18), where R = CgH, is derived from its reaction with oxygen in aqueous alkaline dimethyl sulfoxide or by reaction with hydrogen peroxide and a cooxidant such as sodium hypochlorite or potassium ferricyanide (44). The hydroperoxide (19) has been isolated and independentiy emits light in basic ethanol (45). 

Because of the delay in decomposition of the peroxide, oxygen evolution follows carbon dioxide sorption. A catalyst is required to obtain total decomposition of the peroxides 2 wt % nickel sulfate often is used. The temperature of the bed is the controlling variable 204°C is required to produce the best decomposition rates (18). The reaction mechanism for sodium peroxide is the same as for lithium peroxide, ie, both carbon dioxide and moisture are required to generate oxygen. Sodium peroxide has been used extensively in breathing apparatus. 

Figure 10.23 Effect of Fe(m) ion concentration on rate of hydrogen peroxide decomposition in absence of substrate [237]. Initial concentration 2.9 g/l H202, Sodium silicate 5 g/l, Magnesium sulphate 0.2 g/l, 95 °C, pH 12...

Violence of reaction depends on concentration of acid and scale and proportion of reactants. The following observations were made with additions to 2-3 drops of ca. 90% acid. Nickel powder, becomes violent mercury, colloidal silver and thallium powder readily cause explosions zinc powder causes a violent explosion immediately. Iron powder is ineffective alone, but a trace of manganese dioxide promotes deflagration. Barium peroxide, copper(I) oxide, impure chromium trioxide, iridium dioxide, lead dioxide, manganese dioxide and vanadium pentoxide all cause violent decomposition, sometimes accelerating to explosion. Lead(II) oxide, lead(II),(IV) oxide and sodium peroxide all cause an immediate violent explosion. 

Hydroperoxides decompose in a bimolecular reaction with the formation of water. The activation energy of the peroxide decomposition reaction could be reduced by using some activators, i.e., Fe2+, Cu2+ and sodium hyposulphite, etc. 

K. G. Thurnlackh and K. F. von Hayn prepared a mixed soln. of potassium chlorate and chlorite by the action of potassium hydroxide free from chlorine on a soln. of chlorine dioxide. Light was carefully excluded, and the soln. was evaporated in vacuo at 45°-50°—potassium chlorate separated out first, and after further evaporation, alcohol was added, and the clear alcoholic soln. evaporated. Needle-like crystals of potassium chlorite, KC102, were obtained which deliquesced on exposure to air. As already indicated in connection with the preparation of the acid, G. Bruni and G. Levi made the potassium chlorite by reducing a soln. of potassium chlorate with oxalic acid and A. Reychler, sodium chlorite, by the action of chlorine dioxide on a soln. of sodium peroxide. Sodium chlorite, NaClQ2, can be also made by double decomposition by treating a soln. of barium chlorite with sodium sulphate and evaporating the clear soln. in vacuo. 

Dithionic acid solutions are remarkably resistant to oxidation the cold solutions withstand the attack of hypochlorite, hypobromite and permanganic acid, although on boiling, these reagents become reduced by the sulphur dioxide liberated in the decomposition of the dithionic acid sodium peroxide effects a partial oxidation in the cold.2... 

Various methods for the determination of silicon, particularly from biological samples are available. The techniques usually involve decomposition of the compound to give silica or a silicate by either wet combustion or fusion with sodium peroxide. The silicate formed can then be determined colorimetrically, volumetrically, or gravimetrically. Acidified ammonium heptamolybdate reacts only with monomeric Si(OH)4 and not its oligomers to give a yellow sihcomolybdic acid complex that can be determined spectrophotometrically. This method works... 

SAFETY PROFILE Mldly toxic by ingestion. An experimental teratogen. Experimental reproductive effects. Questionable carcinogen with experimental mmorigenic data. Mutation data reported. Potentially explosive reaction with potassium nitrate + sodium peroxide when heated in a sealed container. Mixtures with alkali release carbon monoxide when heated. When heated to decomposition it emits acrid smoke and irritating fumes. 

DOT CLASSIFICATION 5.1 Label Oxidizer SAFETY PROFILE Dangerous fire hazard by spontaneous chemical reaction. It is a very powerful oxidizer. Fires of this material should be handled like sodium peroxide fires. Moderate explosion hazard hy spontaneous chemical reaction. Explodes on contact with water, forming H2O2 and KOH. Violent reactions with air, Sb, As, O2, K. Vigorous reaction on contact with reducing materials. On contact with acid or acid fumes, it can emit toxic fumes. Incompatible with carbon, diselenium dichloride, ethanol, hydrocarbons, metals. When heated to decomposition it emits toxic fumes of K2O. See also PEROXIDES, INORGANIC. 

Plutonium Dioxide in Molten Equimolar Sodium-Potassium Nitrate. The behavior of plutonium dioxide in molten alkali metal nitrates is an area of major concern. Claims that alkali metal plutonates are formed (1, 2, 3, 5, 6) are not substantiated by definitive analytical results. In some cases (5, 6), sodium peroxide was added as an oxidant to either an alkali metal nitrate melt (6) or to an alkali metal hydroxide melt (5). If the temperature is great enough, for example above 700°C, thermal decomposition of the nitrate melt produces peroxide species. Other studies (4, , 12, 17) do not claim formation of a plutonate species, but only state that an insoluble plutonium-containing compound exists. However, in all the references cited, the results were given for mixed uranium-plutonium dioxide definitive analytical results were not given. 

---