Equations Hydrogen sulphide

Primary thioamides undergo photochemical hydrogen sulphide extrusion in the absence of oxygen (equation 118)173. 

For preparing larger quantities of the hydrosulphide it is more convenient to carry out the reaction in the presence of an excess of the precipitant—say 5 grins, of sodium with a mixture of 10 grms. of absolute alcohol and 100 c.c. of pure dry benzene, more alcohol is added from time to time to keep the ethoxide in soln. until all the sodium is dissolved. This liquid is treated with hydrogen sulphide as before. The reaction seems to be quantitative and to be expressed by the equation C2H50Na+H28=C2H50H+NaHS potassium salt is prepared in a similar manner. 

Pour hydrogen sulphide water into three test tubes and treat it with chlorine, bromine, and iodine water. What is observed Write the equations of the reactions. Arrange the non-metals in a series according to their activity. 

Properties. 1. What odoitr does the evolving gas have Light the hydrogen sulphide with a burning splinter, hold a wet piece of litmus paper over the flame, and watch how its colour changes. Write the equation of the reaction. 

Introduce the cold lid of a crucible into the hydrogen sulphide flame. What appears on the surface of the lid Write the equation of the reaction. 

Pour bromine water, chlorine water, and acidified solutions of potassium permanganate and dichromate into separate test tubes. Pass a stream of hydrogen snlphide through all the tubes. What happens Write the equation of the reactions. What property of hydrogen sulphide is indicated by the occurring phenomena ... 

Pour 1-2 ml of hydrogen sulphide water and a sulphurous acid solution into a test tube. What occurs Write the equation of the reaction. What properties does sulphurous acid exhibit in the given case Identify the products formed when gaseous sulphur dioxide and hydrogen sulphide react. 

Pass a stream of hydrogen sulphide through the nitric acid in the fourth test tube. Write the equation of the reaction. Introduce a small amount of copper sulphide into the fifth tube with nitric acid. Explain why it dissolves in nitric acid. Write the equation of the reaction. 

Pour an ammonium sulphide solution into a potassium chromate or dichromate solution and heat the mixture. How does the solution s colour change What is the composition of the precipitate Write the equation of the reaction. What properties does chromium (VI) exhibit in this reaction How does an acidified potassium chromate or dichromate solution react with hydrogen sulphide, sulphur dioxide, and an iron(II) salt Write the equations of the reactions. 

Reduction of MoIybdenum(VI) and Tungsten VI) Compounds. Pour 3 ml of an ammonium molybdate solution into each of four test tubes, acidify with a 2 N hydrochloric acid solution, and heat up to boiling. Add solutions of sulphuric acid, hydrogen sulphide, and tin(Il) chloride to three of the tubes, respectively, and throw one or two small pieces of zinc into the last tube. Perform similar experiments using sodium tungstate as the initial reactant. Write the equations of the reactions. 

Pour 0.5-1 ml of a potassium permanganate solution into each of three test tubes, acidify with sulphuric acid, and add solutions of iron (I I) sulphate, hydrogen sulphide, and sulphurous acid to them, respectively. How does the solution s colour change Write the equations of the reactions. 

Add a potassium permanganate solution to one of an iron(II) salt acidified with sulphuric acid. What happens Write the equations of the reactions of an iron(II) salt with potassium permanganate and with potassium dichromate. Will an iron(ll) salt be oxidized by chlorine, bromine, and iodine water (see Appendix 1, Table 21) How do iron(II) salts react with hydrogen sulphide and ammonium sulphide ... 

What happens when iron(III) chloride reacts with hydrogen sulphide and ammonium sulphide Conduct the relevant reactions and write their equations. List the properties of iron(III) salts. How can sodium ferrite be prepared Which salts hydrolyze more strongly—ferrites or iron(III) salts What does this depend on ... 

Tin(n) and Tin(IV) Sulphides. Pass a stream of hydrogen sulphide through hydrogen chloride solutions of tin (I I) and tin(IV) chlorides in separate test tubes. What is the colour of the sulphide precipitates Write the equations of the reactions. 

Arsenic(in) and Arsenic(V) Sulphides. Pass a stream of hydrogen sulphide into sodium arsenite and sodium arsenate solutions. What happens Run similar experiments with acidified solutions of the same salts. What do you observe in this case Write the equations of the reactions and explain the occurring phenomena. 

Reaction (5) proceeds until all the hydrogen sulphide is used up when N02 appears and begins to react with the still unconsumed sulphur according to equation (6) ... 

The main polysulphide products are trisulphide, tetrasulphide and pentasulphide, but on account of the tendency of the polysulphides to decompose, yielding thiosulj hate and hydrogen sulphide, the quantity of thiosulphate usually exceeds that indicated in the equation.7 Loss of sulphur by the thiosulphate yields sulphite.8 The so-called lime-sulphur washes, used as insecticides in agricultural work, are obtained by treating sulphur with milk of lime in this way.9... 

Many other metals yield sulphides if treated with gaseous hydrogen sulphide under suitable conditions 8 thus mercury, silver and copper fail to react with dry hydrogen sulphide,9 but if the gas be moist, and especially if oxygen or air also be present, the metals react readily, with formation of the corresponding sulphide, whilst in the presence of oxygen the hydrogen is oxidised to water 10 the reaction for copper is represented by the equation ... 

The interaction of hydrogen sulphide and sulphur dioxide to form water and sulphur, according to the equation... 

Sulphurous acid can, on the other hand, undergo reduction. Hydrogen sulphide reduces it, producing sulphur chiefly. The primary action may be represented by the reversible equation ... 

Hydrogen sulphide slowly decomposes aqueous pentathionic acid, the final state being represented by the equation... 

With hydrogen sulphide the aqueous solution reacts with formation of thiosulphate and sulphur, the equation being... 

Dry liquid hydrogen sulphide reacts in accordance with the equation ... 

The application of thiocyanogen in volumetric analysis is restricted by the necessity of using anhydrous solvents and dry vessels, to avoid hydrolysis. With a sufficient excess of sodium thiosulphate or hydrogen sulphide, respectively, thiocyanogen reacts quantitatively according to the equations ... 

Aqueous solutions of selenic acid will, on heating, oxidise hydrochloric, hydrobromic and hydriodic acids. Hydrogen sulphide gas at any temperature above —10° C. causes decomposition of selenic acid, the rate of reaction increasing both with the temperature and the concentration of the acid. The complete reaction may be represented by the equation... 

The production of the hydrogen sulphide serves to prevent the selenate being oxidised to the ferric state. There may also be a slight secondary reaction resulting in the precipitation of both sulphur and selenium according to the equation on p. 335. From the solution unstable monoclinic crystals of hydrated ferrous selenate, FeSe04.7H20, may be deposited. 

In aqueous solution the acid has a metallic taste and only feebly affects litmus the latter characteristic is in accord with the evidence of its electrical conductivity, which is small and indicates relatively slight dissociation, comparable with that of hydrogen sulphide rather than with that of sulphuric acid. Measurements of the hydrogen-ion concentration of normal telluric acid solution gave [IT ] =4 x 10 5 gram-ion per litre. On the assumption that the acid is ionised in accordance with the equation (see p. 387)... 

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