Hydrogen peroxide sulphide

Redox reactions before titration (e.g. those carried out for the determination of hydrogen peroxide, sulphide or chlorate). 

In addition to the hydrides of formula HjX, oxygen forms the hydride H2O2, hydrogen peroxide, and sulphur forms a whole series of hydrides called sulphanes. These are yellow liquids which are thermodynamically unstable with respect to hydrogen sulphide and sulphur. 

In what way does a solution of hydrogen peroxide react with (a) chlorine water, (b) potassium permanganate solution, (c) potassium dichromate solution, (d) hydrogen sulphide 50 cm of an aqueous solution of hydrogen peroxide were treated with an excess of potassium iodide and dilute sulphuric acid the liberated iodine was titrated with 0.1 M sodium thiosulphate solution and 20.0 cm were required. Calculate the concentration of the hydrogen peroxide solution in g 1" ... 

Hydrogen cyanide Calcium cyanide Potassium cyanide Sodium cyanide Hydrogen fluoride as F Hydrogen peroxide Hydrogen selenide as Se Hydrogen sulphide Hydroquinone... 

Other chemicals Copper and copper alloys are unsuitable for handling hydrogen peroxide " or molten sulphur . Hydrogen sulphide accelerates corrosion of most copper-base materials. In its presence brasses high in zinc are usually found to behave better than other copper alloys. ... 

The simplest procedure for oxidation of sulphides to sulphoxides used till now involves the oxidation of sulphides with hydrogen peroxide alone or in the presence of various catalysts (equation 1). 

TABLE 1. Oxidation of sulphides to sulphoxides, RlR2SO, with hydrogen peroxide... 

A highly selective and rapid oxidation of sulphides to sulphoxides occurs when hydrogen peroxide/selenium dioxide system is used32. The reaction takes place immediately upon addition of a solution of hydrogen peroxide and selenium dioxide to a solution of a sulphide in methanol at room temperature. Yields of sulphoxides (Table 2) are in the range between 80 and 95%. It is most probable that perseleninic acid 19 is the true oxidizing agent. 

A rapid and clean oxidation of sulphides to sulphoxides can also be carried out using the titanium(III) trichloride/hydrogen peroxide reagent35. On a milimole scale, the oxidation takes place in a time shorter than 20 min upon addition of a solution of hydrogen peroxide to a solution of the sulphide and titanium(III) trichloride in methanol at room temperature. It was suggested that the formation of a sulphoxide in this reaction resulted from a direct coupling of the hydroxy radical with cation radical 20 formed at the sulphur atom of the sulphide (equation 6). 

Cyclodextrin mediated oxidation ofprochiral sulphides by achiral oxidation reagents leads also to optically active sulphoxides (e.e. up to 30%). When oxidation was carried out in pyridine the highest optical purities were obtained294 with hydrogen peroxide, whereas in water the best results were observed with m-chloroperbenzoic acid295.. 

Recently, 6-alkylsulphinyl j8-cyclodextrins 6 were obtained from the corresponding sulphides by oxidation with dilute aqueous hydrogen peroxide (equation 2). 

It reacts violently when it is heated with aluminium. It causes hydrogen sulphide to combust. It decomposes hydroxylamine chiorohydrate, hydrogen peroxide (detonation) and potassium azide violently. 

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