Preparation of Hydroxylamine Chloride

Preparation of Hydroxylamine Chloride. Dissolve 7 g of sodium hydroxide in 30 ml of water and saturate the solution with sulphur dioxide to an acid reaction, after which pass the stream of gas through the solution for another five minutes (in a jume cupboard ). Add the solution dropwise with continuous stirring to a solution containing 

5 g of sodium nitrite in 9 ml of water cooled by a mixture of ice and salt. See that the temperature does not rise above 0 °C. Pour the solution into a round-bottomed flask, dilute it to a volume of 150 ml, and heat it to boiling on an electrical flask heater. Perform complete precipitation of the sulphate ions with a solution of barium chloride prepared by dissolving 37 g of barium chloride dihydrate in 45 ml of water. 

Filter off the barium sulphate precipitate and evaporate the solution in a porcelain bowl first on a flame up to one-fourth of its initial volume, and then in a water bath until dry, Rapidly cool the hot bowl with cold water to facilitate the separation of the precipitate. Extract the hydroxylamine chloride from the solution, for which end transfer the triturated substance into a flask with a reflux condenser, pour in 30 ml of ethanol, and heat it on an electric stove with an enclosed heating element up to boiling. Pour off the liquid into a beaker and treat the solid substance again with 15 ml of ethanol. Combine the ethanol extracts, filter them through a crucible with a glass filtering bottom, and then evaporate the filtrate in a water bath up to the beginning of crystallization. 

Filter off the precipitated crystals, collect them (carefully, hydro-xylamine is poisonous ), weigh them, and calculate the yield in per cent. Examine the shape of the crystals under a microscope. Write the equations of the reactions. 

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