Mercury oxide properties

Ozone was discovered in 1785 by the Dutch chemist Van Marum. He observed that when an electric spark passed through oxygen, a product was formed that had a peculiar, irritating odor and that tarnished mercury. Schonhein confirmed Van Marum s observation in 1840 and determined the oxidizing properties of this irritating odor gas. He named it ozone from the Greek word ozo, which means smelling. ... 

Enhancement by strong acids such as TFA is a general feature of oxidations with metal acetates. Metal trifluoroacetates in TFA are much more powerful oxidants (electrophiles) than the corresponding acetates in acetic acid. Activation of the metal oxidant in TFA has been observed with co-balt(III)217 249,259,27S 276 manganese(III),237,275 lead(IV),277-281 thallium-(III),282-287 cerium(IV),288 289 and copper(II).290 Similarly, the electrophilic properties of copper(I)291 and mercury(II)292 acetates are strongly enhanced by replacement of acetate by trifluoroacetate. It has been proposed217,276 that the potent oxidizing properties of Co(III) trifluoroacetate are due to ionization to the cationic Co(III) species,... 

Alkanes can be oxidized in the presence of some transition metal complexes in aqueous and acidic media For example, in concentrated sulfuric acid the oxidative properties of the complexes are enhanced. Solutions of derivatives of palladium(II), platinum(III), manganese(III) and mercury(II) as well as some other compounds (hydrogen peroxide, ammonium persulfate, nitric acid and even concentrated sulfuric acid itself) can be used as oxidants. In the cases of metal-free oxidants the active species are apparently electrophiles such as NO2 or SO3I-C (for nitration of aromatics, see, for example, recent publication [40] and references therein). 

The formal potential of this electrode, Ef" (Hg,HgO) is 0.9258 V [2], Because of its solubility properties, the use of the mercury/mercury oxide electrode is confined to strong alkaline solutions. According to Ives and Janz [2], the mercuric oxide is best prepared by gentle ignition of carefully crystallised mercuric nitrate. The construction is similar to the calomel electrode with an alkaline solution [e.g. saturated Ca(OH)2] instead of the potassium chloride as the electrolyte solution. 

Synonyms Mercuric oxide, red ("Red precipitate ) Mercuric oxide, yellow ( Yellow precipitate") Mercury oxide Chemical Formula HgO (ii) Observable Characteristics — Physical State (as shipped) Solid Color Red Odor None (iii) Physical and Chemical Properties — Physical State at 15 °C and 1 atm. Solid Molecular Weight 216.61 Boiling Point at I atm. Not pertinent (decomposes) Freezing Point Not pertinent ... 

The electrochemical behaviour of silver, mercury, gold, platimmi and vitreous carbon electrodes was examined in chlorosulfonic acid the experiments showed that only the latter material was not attacked the oxidizing properties of chlorosulfonic acid were mainly due to the presence of sulfur trioxide/ As mentioned in Chapter 1, chlorosulfonic acid reacts with powdered selenium or tellurium with the formation of moss-green or cherry-red colours respectively, which may be used as spot tests for the reagent/... 

Acid amides have weakly amphoteric properties, and thus give salts such as CjHsCONHj.HCl with strong acids, and salts of the type C HsCONHNa with strong bases. These compounds have to be prepared at low temperatures to avoid hydrolysis, and are difficult to isolate. The mercury derivatives can, however, usually be readily prepared, because mercuric oxide is too feebly basic to cause hydrolysis of the amide, and the heavy mercuric derivatives crystallise well. 

Strontium [7440-24-6] Sr, is in Group 2 (IIA) of the Periodic Table, between calcium and barium. These three elements are called alkaline-earth metals because the chemical properties of the oxides fall between the hydroxides of alkaU metals, ie, sodium and potassium, and the oxides of earth metals, ie, magnesium, aluminum, and iron. Strontium was identified in the 1790s (1). The metal was first produced in 1808 in the form of a mercury amalgam. A few grams of the metal was produced in 1860—1861 by electrolysis of strontium chloride [10476-85-4]. 

Some metal thiosulfates are inherently unstable because of the reducing properties of the thiosulfate ion. Ions such as Fe " and Cu " tend to be reduced to lower oxidation states, whereas mercury or silver, which form sulfides of low solubiUty, tend to decompose to the sulfides. The stabiUty of other metal thiosulfates improves in the presence of excess thiosulfate by virtue of complex thiosulfate formation. 

Trifluoroacetates of silver, mercury(II), thallium(lll), lead(IV), and lodme(III) are synthetically valuable reagents that combine the properties of strong electrophiles, oxidizers, and Lewis acids Furthermore, trifluoroacetate anions are stable to oxidation, are weak nucleophiles, and usually do not cause any contamination of the reaction mixture... 

Monoalkylthallium(III) compounds can be prepared easily and rapidly by treatment of olefins with thallium(III) salts, i.e., oxythallation (66). In marked contrast to the analogous oxymercuration reaction (66), however, where treatment of olefins with mercury(II) salts results in formation of stable organomercurials, the monoalkylthallium(III) derivatives obtained from oxythallation are in the vast majority of cases spontaneously unstable, and cannot be isolated under the reaction conditions employed. Oxythallation adducts have been isolated on a number of occasions (61, 71,104,128), but the predominant reaction pathway which has been observed in oxythallation reactions is initial formation of an alkylthallium(III) derivative and subsequent rapid decomposition of this intermediate to give products derived by oxidation of the organic substrate and simultaneous reduction of the thallium from thallium(III) to thallium(I). The ease and rapidity with which these reactions occur have stimulated interest not only in the preparation and properties of monoalkylthallium(III) derivatives, but in the mechanism and stereochemistry of oxythallation, and in the development of specific synthetic organic transformations based on oxidation of unsaturated systems by thallium(III) salts. 

Group IIB includes Zn, Cd and Hg. Zinc has some resemblance to magnesium but the other metals in the group have little in common. At room temperature mercury is unaffected by air, water or non-oxidizing agents whereas zinc is more reactive, albeit tempered by a protective hydroxide film, a property utilized in galvanizing. 

A liquid gallium electrode has similar properties to the mercury electrode (at temperatures above 29°C), but it has a far greater tendency to form surface oxides. 

Find the pore size distribution of pellets of uranium oxide with these properties. True density = 7.57 g/cc, particle density =3.2 g/cc, porosity = 57.8% Measurements were made of the penetration of Mercury, cc/gm of pellet, against pressure in psi. 

The mercuric ion, Hg2 +, which is obtained after oxidation in the red blood cells and other tissues, is able to form many stable complexes with biologically important molecules or moieties such as sulphydryl groups. The affinity of mercury for sulphydryl groups is a major factor in the understanding of the biochemical properties of mercuric compounds, resulting in interference with membrane structure and function and with enzyme activity. 

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