Oxides fresh

Strontium is softer than calcium and decomposes in water more vigorously. It does not absorb nitrogen below 380oC. It should be kept under kerosene to prevent oxidation. Freshly cut strontium has a silvery appearance, but rapidly turns a yellowish color with the formation of the oxide. The finely divided metal ignites spontaneously in air. Volatile strontium salts impart a beautiful crimson color to flames, and these salts are used in pyrotechnics and in the production of flares. Natural strontium is a mixture of four stable isotopes. 

Tetra(o-aminophenyl)porphyrin, H-Co-Nl TPP, can for the purpose of electrochemical polymerization be simplistically viewed as four aniline molecules with a common porphyrin substituent, and one expects that their oxidation should form a "poly(aniline)" matrix with embedded porphyrin sites. The pattern of cyclic voltammetric oxidative ECP (1) of this functionalized metal complex is shown in Fig. 2A. The growing current-potential envelope represents accumulation of a polymer film that is electroactive and conducts electrons at the potentials needed to continuously oxidize fresh monomer that diffuses in from the bulk solution. If the film were not fully electroactive at this potential, since the film is a dense membrane barrier that prevents monomer from reaching the electrode, film growth would soon cease and the electrode would become passified. This was the case for the phenolically substituted porphyrin in Fig. 1. 

Specific surface area and Pb adsorption capacity of biogenic Mn oxide, fresh abiotic Mn oxide precipitate and pyrolusite minerals. 

Material Erlenmeyer flask, thermometer pieces of calcium oxide (fresh), water. 

The solids have been prepared by solid-state reaction in air, of pure V(V), Sb(III) y Ti(IV) oxides. Fresh samples have been characterised by Temperature programmed reduction (TPR) and catalytic tests. For Vo 8SbTio.204 catalysts, elemental C-H-N-O analysis was performed on fresh and used samples. 

They investigated both the fresh and spent catalysts by using temperature programmed reduction technique. The bimetallic catalysts exhibit much lower Au reduction temperature compared to Au/Fc203. The X-ray diffraction measurements show that there is no evidence for mixed metal species (Au-Ru) either in fresh or spent catalysts. TPR analysis of the spent Au-Ru/iron oxide catalyst revealed the presence of the reduction signal due to AU Oy species at a Tmax of 155 °C, which suggests the lowering in the reduction temperature which is found at 161 °C in the Au-Ru/iron oxide fresh catalyst. 

HI-HCl elutriant. 1 ml of HI stock solution is added to 9 ml of cone. HCl to give a solution about 0.44 M in HI. The precipitate which results from the hydrazine present is removed by centrifugation and the supernate is saturated with gaseous HCl. The solution is permitted to come to equilibrium at room temperature before use and since the solution is readily oxidized, fresh reagent is required every few days. 

Oxidation. Freshly spilled crude oil has a natural tendency to oxidize in air. Sunlight and turbulence stimulate the process. Oxidation products include organic acids, ketones and aldehydes, all of which tend to dissolve in water. As a spill ages, oxidation slows as easy molecules disappear from the mix. Compared to other natural forces, oxidation plays a minor role in removing oil spills. 

---