4 HYPONITRITE FROM NITRITE THROUGH 



quantity of sodium carbonate (10.8 grams anhydrous) is found 

 to be required, including that for the three or four drops of 

 sulphuric acid added. The approximately monohydrated car- 

 bonate, in fine powder, is quickly shaken thoroughly with the 

 solution, so as to hinder its caking, and the last portions of it then 

 dissolved up by warming the flask. The solution of oxyamido- 

 sulphonate and sulphate, thus prepared, contains almost exactly 

 only half its weight of water, is therefore supersaturated, and 

 is the strongest solution practically obtainable ; it will be found 

 to approach closely 113 grams in weight, so smoothly do the 

 reactions proceed. To make a weaker solution and then con- 

 centrate it by evaporation is easy enough, but the adjustment 

 is troublesome and the formation of hard cakes of sodium 

 sulphate, which interferes with the proper working of the next 

 stage of the operation, is difficult to avoid. 



The flask is well drained of its contents into a basin, pre- 

 ferably a hemispherical nickel basin or, lacking that, a stout 

 porcelain one, of capacity not much less than 500cc. Potassium 

 hydroxide, free from chloride, assayed for real alkali and for 

 water, and liavino* not less than — and not more than 1 mol. 

 water to 1 of the hydroxide, is now needed ; for if it were 

 anhydrous it would cause much heating and consequent decom- 

 position of the salts. Generally, the potassium hydroxide 

 purified by alcohol and the more translucent varieties of stick 

 potash contain about the right proportion of water and then 



hydroxylamine to ammonia and is inactive upon oxyamidosulphonate. Testing in this way, 

 no odour of ammonia has been recognisable and moist red litnms i)aper held in the bottle 

 has been barely affected. Kirschner, using potassium oximidosulphonate, had to heat to boil- 

 ing to effect hydrolysis, whicli is dithcult then to complete witliout some of tlie oxyamido- 

 sulphonate passing on into hydroxylamine. "When the hydrolysis is underdone, there will 

 be nitrite regenerated later on by the alkali ; and when it is overdone there will also be 

 nitrite formed during the oxidation of the hydroxylamine by tlie silver (ur mercury) oxide. 



