NASCENT HYDKOGEN AND HYDKOXYLAMINE. 249 



SIMILAR OXIDATION OP THE SULPHATE. 



(NH 3 ) 2 H 2 S0 4 diss. + = (NH 3 0) 2 H 2 S0 4 diss - 5-7 



(NH 3 ) 2 H 2 S0 4 cryst. + = (NH 3 0) 2 H 2 S0 4 cryst - 4-1 



We see that a fixed oxidation would absorb quantities of heat 

 varying from 2 '6 to 7 '2; according to whether it takes 

 place on free hydroxylamine or on its salts in solution. It is 

 essential to note that this quantity is negative, unlike what 

 takes place for oxides of nitrogen. 1 Moreover, the three above- 

 mentioned reactions are purely theoretical ; they are, however, 

 worthy of mention, as by their endothermal nature they may be 

 compared to the formation of oxygenated water and to that of 

 nitrogen monoxide. 



We get for the formation of hydroxylamine by the hydrogena- 

 tion of nitric oxide 



NO + H 3 + water = NH 3 diss. + 40-6. 



This last reaction is effected, in fact, by means of nascent 

 hydrogen, that is to say, in reactions which furnish, in addition, 

 the heat which would have been given off at the time of the 

 formation of the free hydrogen, under the same conditions. 



8. Eeactions of hydroxylamine. Action of hydrogen 



NH 3 dissolved + H 2 = NH 3 H 2 dissolved + 71*0. 



We see by this that the hydroxylamine will be easily changed 

 into ammonia by the nascent hydrogen. This is why the 

 production of the first body, in the reduction of the oxides of 

 nitrogen, requires very special conditions. Among all the 

 formations of nitric compounds that nitric acid can effect by 

 producing oxidation, that of hydroxylamine gives off the least 

 heat. In fact, each equivalent of oxygen imparted by the 

 dilute nitric acid to the body to be oxidised with the formation 

 of hydroxylamine gives off 16*4 Gal. less than free oxygen, 

 whereas the free formation of ammonia gives off only 12'1 Gal. 

 less, that of nitric oxide - 12 Gal., that of nitric peroxide 

 - 9-6 Gal, that of nitrogen -14 Gal., etc. 2 



9. Action of oxygen. Heat of combustion 



2NH 3 dilute + = 2 + 3H 2 liquid + 84'5. 



The combustion of dilute ammonia gives off a little less, or 

 -f 82*5 ; but it requires three times as much oxygen for the 

 same weight of nitrogen contained in the compound. 



We get 



2NH 3 dilute + 2 = N 2 gas + 3H 2 liquid +74-2 



4NH 3 + 5 = N 4 3 dilute + 6H 2 liquid + 65'4 



2NH 3 +0 4 = N 2 3 + 3H 2 +80-3 



2NH 3 ,; +0 5 = 2HN0 3 :: + 2H 2 +98-8 



1 p. 171, nitric oxide ; pp. 178 and 179, nitrogen trioxide ; p. 189, nitric 

 peroxide. 



2 See p. 200. 



