76 NON-METALS AND THEIR COMBINATIONS. 



Composition. 



By weight. By volume. 



NO NO 



Nitrogen monoxide, N 2 0, 28 16 2 1 



" dioxide, N,0 2 = 2(NO), 28 32 22 



" trioxide, N 2 O 3 , 28 48 23 



" tetroxide, jST 2 4 = 2(NO 2 ), 28 64 24 



" pentoxide, N 2 5 , 28 80 25 



The first, third, and fifth of these compounds are capable of 

 combining with water to form acids, known as hyponitrous, 

 nitrous, and nitric acid, respectively. 



Nitrogen monoxide, N 2 = 44, (Sometimes called nitrous 

 oxide ; also, laughing gas). This compound may be easily ob- 

 tained by heating ammonium nitrate in a flask at a temperature 

 not exceeding 250, when the salt is decomposed into nitrogen 

 monoxide and water : 



NH 4 N0 3 = 2H 2 + N 2 0. 



Nitrogen monoxide is a colorless, almost inodorous gas, of 

 distinctly sweet taste. It supports combustion almost as ener- 

 getically as oxygen, but differs from this element by its solu- 

 bility in cold water, which absorbs nearly its own volume. The 

 most characteristic feature of this gas is the intoxicating power 

 it exerts upon the animal system. It is frequently used as an 

 anaesthetic in dental surgery. 



Nitrogen dioxide, NO = 30. This is a colorless gas which is 

 generally formed when nitric acid acts upon metals or upon 

 substances which deoxidize it. It is capable of combining 

 directly with one more atom of oxygen, thereby forming ]ST0 2 , 

 nitrogen tetroxide, which is a gas of a deep red color. Nitrogen 

 trioxide is of no practical interest. 

 



Nitric acid, Acidum nitricum, HN0 3 = 63 (Hydric nitrate}. 

 Nitrogen pentoxide is of scientific interest only. "When brought 

 in contact with water it readily combines with it, forming nitric 

 acid : 



NO + HO = 2HNO,. 



