186 OXYGENATED COMPOUNDS OF NITEOGEX. 



This formula accounts for the existence of the acid salts, 

 observed by Zorn. 



Silver hyponitrite is decomposed by heat, with formation of 

 nitric oxide, nitrogen trioxide, and metallic silver 



Ag 4 NA = 2X0 + NA + Ag 4 . 



But the nitrogen trioxide reacts partially upon the silver, so 

 as to reproduce a certain quantity of nitrite, and even nitrate 

 of silver. 



3. By decomposing silver hyponitrite by a dilute acid, 

 hyponitrous acid is obtained in an aqueous solution. This acid 

 is not at all stable. Its solutions raised to boiling point are 

 decomposed, yielding nitrogen monoxide mixed with nitrogen, 

 retaining at the same time a certain quantity of dilute nitric 

 acid 



4NA dilute + H 2 = 7T 2 + 2HN0 3 . 



On contact with the air they absorb oxygen slowly, becoming 

 changed into nitric acid. 



4. We have, with a view to calorimetric tests, methodically 

 subjected hyponitrous acid to the action of the three following 

 oxidising bodies iodine, bromine, and potassium permanganate. 



(1) A solution of iodine in potassium iodide did not exert 

 any appreciable action on the hyponitrous acid combined with 

 the silver 1 or previously liberated by an equivalent quantity 

 of dilute hydrochloric acid. 



(2) The oxidation by bromine is very characteristic. A 

 known weight of silver hyponitrite, 2 grms., was mixed with 

 hydrochloric acid in excess, and an aqueous solution of bromine, 

 also slightly in excess, the strength of which was determined ; 

 the reaction was allowed to go on for some time, when the 

 excess of bromine was determined. This method tends to give 

 rather high figures, owing to the evaporation of some traces of 

 bromine. 



Or the hydrochloric acid may be mixed beforehand with 

 bromine water in which salts of silver have been dissolved 

 (series I.) ; or the salt dissolved in the acid and the bromine 

 added (series II., p. 187). 



The equivalent ratio between the silver and bromine employed 

 has been found to be very nearly 1 : 3 '5, which agrees with the 

 formula. 



Ag 4 N A + 7H 2 + 14Br = 4HX0 3 + 1 OHBr + 4 AgBr. 



The formula AgNO would require the ratio 1 : 4, which is 

 greatly higher than all the quantities observed. 



(3) The oxidation by potassium permanganate gives rather 

 irregular results, the oxygen absorbed varying from 4'6 to 8'9 

 per cent., and the action going on almost indefinitely. However, 



1 Except the conversion of the silver into iodide. 



