Preparation of Hydrazine Sulphate

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 30 ml of a 35% sodium hydroxide solution into a 250-ml beaker provided with a mechanical mixer, a thermometer, and a dropping funnel reaching almost to the bottom of the beaker. Cool the beaker with a mixture of ice and sodium chloride, switch on the mixer, and introduce a catalyst—a solution of 0.3 g of manganese(II) sulphate pentahydrate or 0.1 g of manganese(II) chloride tetrahydrate in 1 ml of water. Cool the solution to 0 °C and introduce 7 g of urea into it. Lower the temperature to 5-7 °C below zero and gradually add 63 ml of the filtered sodium hypochlorite solution cooled to the same temperature from the dropping funnel. The temperature even at the end of the reaction must not rise above 10 °C. 

After the sodium hypochlorite solution has been added, stir the reaction mixture during 10 min, and then slowly (two degrees a minute) heat the solution on a water bath up to 63-65 °C (use a thermometer ), after which cool the reaction mixture to room temperature. 

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  

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