Peculiar Properties of Water 101 



Water possesses properties which are different from other liquids. 

 Some of these are: 



(1) The large density relative to its molecular weight and the 

 way in which it changes with the temperature. 



(2) The change in compressibility with temperature. 



(3) The high specific heat and its change with temperature. 



(4) A very large latent heat of vaporization. 



(5) The magnitude of its dielectric constant. 



(6) Solvent power. 



(7) Remarkable tendency toward secondary valence combination 

 or hydration. 



(8) Notable ionizing power. 



Liquid water is largely composed of dihydrol in which may be dis- 

 solved some steam molecules or monohydrol and some ice molecules, 

 sometimes called trihydrol. Equilibria between these three kinds of 

 molecular arrangement occurs, so that the variation in the physical 

 properties of water with the temperature is explained. 



Oxygen imparts a polarity to the water molecule which causes it 

 to unite into the remarkably compact dihydrol. The polarity is largely 

 responsible for the secondary chemical reactions, the high dielectric 

 constant as well as the solvent and ionizing powers. 



In addition to the polarity there are certain specific characteristics 

 of water of a chemical character that have a notable effect on its 

 secondary valence or physico-chemical reactivity. 



The structures of methane, ammonia and hydrofluoric acid are 

 given according to the Lewis theory and the explanation of their chemical 

 and physical properties is suggested. 



The application of these ideas to organic chemistry is indicated. 



