Oxidising gases dioxide

The presence of chloric(I) acid makes the properties of chlorine water different from those of gaseous chlorine, just as aqueous sulphur dioxide is very different from the gas. Chloric(I) acid is a strong oxidising agent, and in acid solution will even oxidise sulphur to sulphuric acid however, the concentration of free chloric(I) acid in chlorine water is often low and oxidation reactions are not always complete. Nevertheless when chlorine bleaches moist litmus, it is the chloric(I) acid which is formed that produces the bleaching. The reaction of chlorine gas with aqueous bromide or iodide ions which causes displacement of bromine or iodine (see below) may also involve the reaction... 

Liquid chlorine dioxide, ClOj, boils at 284 K to give an orange-yellow gas. A very reactive compound, it decomposes readily and violently into its constituents. It is a powerful oxidising agent which has recently found favour as a commercial oxidising agent and as a bleach for wood pulp and flour. In addition, it is used in water sterilisation where, unlike chlorine, it does not produce an unpleasant taste. It is produced when potassium chlorate(V) is treated with concentrated sulphuric acid, the reaction being essentially a disproportionation of chloric(V) acid ... 

Action of chlorine trifluoride causes incandescence [1]. Manganese dioxide catalytically decomposes powerful oxidising agents, often violently. Dropped into cone, hydrogen peroxide, the powdered oxide may cause explosion [2], Either the massive or the powdered oxide explosively decomposes 92% peroxomonosulfuric acid [3], and mixtures with chlorates ( oxygen mixture , heated to generate the gas) may react with explosive violence [4], Cuban pyrolusite can be used in place of potassium dichromate to promote thermal decomposition of potassium chlorate in match-head formulations [5],... 

Most recently, a highly unusual membrane composition was reported from anaerobic ammonium-oxidising (anammox) bacteria. In these bacteria, nitrite is reduced, nitrogen gas generated, and carbon dioxide is converted into organic carbon, as the consequence of ammonia reduction. This central energygenerating process can be described as ... 

Some new concepts have been deduced in the context of the three-step model, for example, the conversion system, the conversion gas, the conversion efficiency, and the combustion efficiency. Two new physical quantities have been associated with the conversion gas. The physical quantities are referred to as the mass flow and the stoichiometry of the conversion gas. The conversion efficiency is a measure of how well the conversion system performs, that is, the degree of solid-fuel convertibles that are converted from the conversion system to the combustion system. The combustion efficiency is defined as the degree of carbon atoms being oxidised to carbon dioxide in the combustion system. In other words, the combustion efficiency is a measure of the combustion system performance. 

The substance is best prepared by dissolving cobaltous carbonate in the smallest possible quantity of hydrochloric acid, treating the cold solution with a mixture of concentrated aqueous ammonia and ammonium carbonate, and oxidising by means of a stream of air drawn through the liquid. When oxidation is complete ammonium chloride is added and the whole evaporated to a syrup dilute hydrochloric acid is added to remove carbon dioxide, and the liquid is saturated with ammonia gas to decompose any tetrammino-salt formed. On the addition of concentrated hydrochloric acid the salt crystallises out on cooling.6... 

Sulphur Dioxide as an Oxidising Agent.—Sulphur dioxide does not support the combustion of most substances which burn in oxygen, but many metals, e.g. sodium, potassium, magnesium and finely divided lead, when heated in a stream of the gas undergo conversion into a mixture of sulphide and oxide or sulphite, so much heat being liberated that the mass becomes incandescent in the case of the alkali metals some thiosulphate also may be formed.12... 

Other chemical processes in which sulphur dioxide functions as an oxidising agent include the interaction of sulphur dioxide with stannous chloride or titanous chloride in aqueous solution containing hydrochloric acid, when the salts are converted into the corresponding tetrachlorides 5 also the interaction of the gas with organo-magnesium compounds, when the organic sulphide is produced to some extent.6... 

Occasionally it is desired to determine sulphurous acid by a gravimetric method it is then usual to expel the sulphur dioxide from the solution under examination by distilling in an atmosphere of carbon dioxide and oxidise the gas to sulphuric acid by absorption in bromine water or iodine solution, subsequently adding barium chloride and weighing the precipitated barium sulphate. This method also gives accurate results volumetrieally if steps are taken to prevent loss of iodine by volatilisation in the current of carbon dioxide. The excess iodine is titrated with a solution of sodium thiosulphate.8... 

When passed over heated iron boride, the gas interacts, forming iron selenide and selenium boride.7 With water no stable compound is produced, although the existence of an unstable crystalline hydrate has been observed.8 Sulphur dioxide and selenium dioxide oxidise a solution of hydrogen selenide, the product in the latter case being red selenium 9... 

Hydrogen telluride burns in air with a blue flame, producing water and tellurium dioxide. Moist air decomposes the gas immediately even at the ordinary temperature with liberation of black tellurium. The dry gas is immediately oxidised by oxygen. 

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