THE USE OF LIQUID AMMONIA AS A 



SOLVENT 



By PERCY MAY, B.Sc. 



Introduction 



A knowledge of the conditions governing the course of a 

 chemical action can be gained most rapidly when the interact- 

 ing substances are in a liquid state. For instance, changes of 

 concentration can be measured from time to time and hence 

 the velocity and " order " of the action can be found ; thermal 

 changes or volume changes can also be easily measured. 



In recent years much attention has been paid to the part 

 played by the nature of the solvent in influencing the course 

 and velocity of an action and the work done in this direction 

 brings into prominence an interesting contrast between the two 

 main branches of Chemistry — Organic and Inorganic. The 

 number of organic solvents in common use is very great 

 Alcohol, ether, chloroform, carbon tetrachloride, carbon disul- 

 phide, acetone, glacial acetic acid, benzene, light petroleum and 

 many others are frequently employed and these show a great 

 variety both in their chemical and physical properties. As an 

 example of the influence of the solvent may be mentioned the 

 interaction of triethylamine and ethyl iodide : in presence of 

 acetone the action takes place ten times as rapidly as it does in 

 benzene and about four hundred times as quickly as in heptane. 



On the other hand, comparatively few substances other than 

 water have been used as solvents for inorganic compounds. 

 Systematic inorganic analysis has been founded on the behaviour 

 of such solutions and, owing to the attention paid to them, our 

 knowledge of both their chemical and physical properties greatly 

 exceeds that which we possess of the corresponding properties 

 of non-aqueous solutions. 



During the last decade or two, however, a great deal of 

 work has been done on other solvents of acids, salts, bases and 

 simple inorganic compounds, more especially with regard to 

 their physical properties, such investigations being intimately 



