220 



SMITH'S INTERMEDIATE CHEMISTRY 



employed. This discharge gives ozone very easily, because its 

 use involves no rise in temperature whatever. 



30 2 TT 20 3 . 



The poles of the induction coil are attached to the tinfoil upon 

 the outside of the outer tube and the inside of the inner tube 

 (Fig. 63). The " discharge " therefore passes through two layers 



FIG. 63 



of glass, as well as through the oxygen. The oxygen, from a 

 cylinder of the gas, flows slowly through the space between the 

 tubes. At best, only 6 to 7 per cent of the oxygen is usually 

 changed into ozone. 



Physical Properties. Ozone (Greek, to smell) is a gas of 

 deep blue color, with a fresh, highly individual odor. It is more 

 easily liquefied (b.-p. 119) than is oxygen, and is also much 

 more soluble in water. Its density is one-half greater than that 

 of oxygen, and the formula Oa records this fact. When a simple 

 substance shows more than one form in the same state, like oxygen 

 and ozone, we call them allotropic modifications. Ice (p. 64) 

 exists in at least five allotropic modifications. 



Chemical Properties. Ozone is at rather low temperatures 

 (e.g., from 10 to 500) the kss stable form of the element. Upon 

 standing, and more quickly when warmed, it changes into oxygen, 

 with liberation of the additional energy it contains. 



Being possessed of more internal energy than oxygen, ozone 

 oxidizes the same substances as does oxygen, only more rapidly 

 and vigorously. For the same reason it oxidizes many substances 



