Hydrogen peroxide physical properties

Table 2. Physical Properties of Aqueous Hydrogen Peroxide...

Because the reaction takes place in the Hquid, the amount of Hquid held in the contacting vessel is important, as are the Hquid physical properties such as viscosity, density, and surface tension. These properties affect gas bubble size and therefore phase boundary area and diffusion properties for rate considerations. Chemically, the oxidation rate is also dependent on the concentration of the anthrahydroquinone, the actual oxygen concentration in the Hquid, and the system temperature (64). The oxidation reaction is also exothermic, releasing the remaining 45% of the heat of formation from the elements. Temperature can be controUed by the various options described under hydrogenation. Added heat release can result from decomposition of hydrogen peroxide or direct reaction of H2O2 and hydroquinone (HQ) at a catalytic site (eq. 19). 

Barium is a member of the aLkaline-earth group of elements in Group 2 (IIA) of the period table. Calcium [7440-70-2], Ca, strontium [7440-24-6], Sr, and barium form a closely aUied series in which the chemical and physical properties of the elements and thek compounds vary systematically with increa sing size, the ionic and electropositive nature being greatest for barium (see Calcium AND CALCIUM ALLOYS Calcium compounds Strontium and STRONTIUM compounds). As size increases, hydration tendencies of the crystalline salts increase solubiUties of sulfates, nitrates, chlorides, etc, decrease (except duorides) solubiUties of haUdes in ethanol decrease thermal stabiUties of carbonates, nitrates, and peroxides increase and the rates of reaction of the metals with hydrogen increase. 

Table 14,11 Some physical properties of hydrogen peroxide ...

Hydrogen peroxide, when pure, is an almost colourless (very pale blue) liquid, less volatile than water and somewhat more dense and viscous. Its more important physical properties are in Table 14.11 (cf. H2O, p. 623). The compound is miscible with water in all proportions and forms a hydrate H2O2.H2O, mp —52°. Addition of water increases the already high dielectric constant of H2O2 (70.7) to a maximum value of 121 at 35% H2O2, i.e. substantially higher than the value of water itself (78.4 at 25°). 

The physical properties of hydrogen peroxide indicate that hydrogen peroxide injection has the potential of combining the more favorable aspects of many enhanced oil-recovery processes, namely ... 

The rubbery character and particular physical and chemical properties of polyisobutene stem from its paraffinic origins. Its outstanding properties are its low glass transition temperature, very low water vapor permeability and resistance to many chemicals. At room temperature polyisobutene is resistant to dilute and concentrated mineral acids and bases, as well as hydrogen peroxide. 

The accumulation of hydrogen peroxidase affects many intracellular processes and results in hemolysis. These include the cross-linking of membrane proteins hemoglobin denaturation (manifest as Heinz body formation), which in turn affects the physical properties of the erythrocyte and lipid peroxidation, which may affect the cell membrane to cause direct hemolysis (Fig. 11-8). The resultant damage leads to a mixture of intravascular hemolysis and extravascu-lar hemolysis (by which hemolysis occurs in the reticuloendothelial system). In acute hemolytic episodes, the clinical picture is of predominantly intravascular hemolysis, while predominantly extravascular hemolysis is seen in patients with chronic hemolysis. 

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