Hydrazine sulphate

Procedure for Bromine and Iodine Estimations. Again cover the beaker as before, but before adding the nitric acid add i g. of hydrazine sulphate and heat the solution on the water-bath until evolution of gas ceases. To ensure complete decomposition of an iodate, however, the heating should be continued for i hour. 

Hydrazine hydrate of 60 per cent, and 100 per cent, are available commercially. The preparation from hydrazine sulphate is hardly worth while. 

The reaction represented is that with hydrazine solution, produced from hydrazine sulphate and sodium acetate in the presence of aqueous alcohol. Excellent results are also obtained by interaction of the commercially available 60-64 per cent, hydrazine solution with a solution of 2 4 dinitrochloro-benzene in triethylene glycol or in diethylene glycol at about 20°. 

Suspend 35 g. of finely-powdered hydrazine sulphate in 125 ml. of hot water contained in a 400 ml. beaker, and add, with stirring, 118 g. of crystallised sodium acetate or 85 g. of potassium acetate. Boil the mixture for 5 minutes, cool to about 70°, add 80 ml. of rectified spirit, filter at the pump and wash with 80 ml. of hot rectified spirit. Keep the filtered hydrazine solution for the next stage in the preparation. 

Stir a mixture of 2-4 g. of powdered hydrazine sulphate, 18 ml. of water and 2-4 ml. of concentrated aqueous ammonia (sp. gr. 0-88), and add 4-6 g. (4 4 ml.) of benzaldehyde (free from benzoic acid) dropwise, with stirring, over a period of 30-60 minutes. Stir the mixture for a further hour, collect the solid by suction filtration and wash it with water. RecrystalUse from 8 ml. of rectified spirit. The 3 ield of benzalazine (yellow needles), m.p. 92-93°, is 3-6 g. 

Dimethylpyrazole (III) may be prepared from acetylacetone (I) and hydrazine (II) (produced from hydrazine sulphate and aqueous alkali). The reaction may be represented as ... 

Dissolve 65 g. of hydrazine sulphate in 400 ml. of 2 5. V sodium liyd i oxide solution contained in a 1-htre three-necked flask, equipped with a thermometer, mechanical stirrer and dropping funnel. Immerse the flask in an ice bath and when the temperature reaches 15° (some sodium sulphate... 

Benzil monohydrazone. Method 1. Boil a mixture of 26 g. of hydrazine sulphate, 55 g. of crystallised sodium acetate and 125 ml. of water for 5 minutes, cool to about 50°, and add 115 ml. of methyl alcohol. Filter off the precipitated sodium sulphate and wash with a little alcohol. Dissolve 25 g. of benzil (Section IV,126) in 40 ml. of hot methyl alcohol and add the above hydrazine solution, heated to 60°. Most of the benzil hydrazone separates immediately, but reflux for 30 minutes in order to increase the yield. Allow to cool, filter the hydrazone and wash it with a httle ether to remove the yellow colour. The yield is 25 g., m.p. 149-151° (decomp.). 

Hydrazine sulphate reacts with sodium cyanate in the presence of sodium carbonate to give semicarbazide, which remains in solution ... 

No satisfactory direct gravimetric procedure is available but nitrite can be oxidised to nitrate by permanganate or cerium(IV) and then determined in that form. The determination of total nitrate + nitrite is an important analysis, e.g. for soil samples. Nitrite may be destroyed using urea, sulphamic acid or hydrazine sulphate the reaction with the former is ... 

Sodium ammonium hydrogenphosphate Ammonium hydrogensulphride Anunonium sdlphamate Hydrazine sulphate Ammonium phosphate Diammonium sulphite Ammonium thiosulphate Ammonium molybdate Amnwnium sulphate Diammonium peroxodlsutphate... 

Hydrazine sulphate (52 g.) and 21 g. of anhydrous sodium carbonate are dissolved in 200 c.c. of boiling water. The solution is cooled to 50°, a solution of 35 g. of potassium cyanate in 100 c.c. of water is added, and the whole is allowed to stand over night. After small amounts of hydrazodicarbonamide, produced in the reaction H2N.CO.NH.NH2 + 0=C=NH —> H2N.CO.NH.NH.CO.NH2, have been removed by filtration, 60 c.c. of acetone are added to the solution, which is again allowed to stand, with frequent shaking, for twenty-four hours. The acetone semicarbazone which has then crystallised out is filtered dry at the pump, washed with a little water, and dried on a porous plate or in vacuo. 

Properties. 1. Pour 5 ml of water into each of two test tubes, and introduce 2-3 drops of hydrazine, hydrazine hydrate, or several crystals of hydrazine sulphate into them. Add several drops of iodine water into one tube. What is observed Write the equation of the reaction. Add solutions of copper(II) chloride and an alkali into the other tube. Carefully heat its contents. What happens Write the equation of the reaction. What properties do hydrazine compounds have ... 

What is the structure of hydrazine, hydrazine hydrate, hydrazine sulphate, and hydroxylamine Do these compounds exhibit oxidizing properties ... 

Preparation of Hydrazine Sulphate. Perform the experiment in a fume cupboard ). Preliminarily prepare a sodium hypochlorite solution. To do this, spill 100 g of ice (prepared from distilled water in the freezing chamber of a refrigerator) into a 300-ml flask and add a sodium hydroxide solution (dissolve 50 g of sodium hydroxide in 100 ml of water). Put the flask in a bath with ice. Pass chlorine during two hours into the cooled solution. When doing this, see that the temperature does not rise above 5 °C. 

Pour 70 ml of a 50% sulphuric acid solution into a porcelain beaker. Add the obtained solution to it from the dropping funnel while vigorously mixing wear eye protection ). The temperature must not rise above 40-50 °C. Cool the solution to 22-25 °C not lower ). Filter off the hydrazine sulphate precipitate. Wash it three times with 10-ml portions of water. Dry it in a drying cabinet at 50-70 °C. Weigh the substance. Write the equations of the reactions. Calculate the yield in per cent. How can you convince yourself that the preparation obtained is hydrazine sulphate ... 

Preparation of Hydrazine Hydrate. Assemble an apparatus as shown in Fig. 85a. Grind 30 g of solid potassium hydroxide into a powder in a porcelain mortar wear eye protection ). Add 30 g of hydrazine sulphate to the powder and thoroughly mix the reactants. 

Many authors recommend the precipitation of cuprous acetylide in the presence of reducing substances such as hydroxylamine (Ilosvay [111]), S02 (Rupe[112]), hydrazine sulphate (Cattelain [113]), so as to avoid contamination with cupric acetylide. 

In an aqueous solution containing ammonium perdisulphate only, the ammonium radical is gradually converted into nitric acid, this reaction explaining why the decomposition of ammonium perdisulphate diverges somewhat from the simple unimolecular course 4 (p. 183). Hydrazine in aqueous solution, prepared by the addition of an alkali to hydrazine sulphate, is similarly oxidised to nitrogen by perdisulphates 5... 

The most generally trustworthy procedure for the estimation of a perdisulphate is to boil the neutralised solution for half an hour and then measure the resulting acidity 6 the method may be modified by the successive addition of a neutralised solution of hydrazine sulphate and of a known volume of standard alkali hydroxide, when the sulphuric acid first produced during the course of the reaction... 

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