CHAPTER II - LIQUID AMMONIA

Abstract

Publisher Summary This chapter focuses on liquid ammonia chemistry. Liquid ammonia is a familiar solvent in organic chemistry. It is also used in inorganic chemistry for the production of unusual valence states, unusual metathetic reactions, and in reactions where hydrolysis would be a restriction. The extensive use of liquid ammonia is readily explained by the fact that of all nonaqueous solvents, liquid ammonia approaches most closely to water in its physical properties. The chapter presents a comparison of the physical properties of ammonia and water. Like water, the heats of fusion and the heats of vaporization of ammonia are higher than those of other hydrides in the same group of the periodic classification. This indicates a considerable degree of structural association in the liquid and solid states attributable to hydrogen bond formation; however, the dipole moments indicate that the extent of association is less with ammonia than with water. The lower intermolecular attraction means lower viscosity and, hence, a high mobility of ions in liquid ammonia. Ammonia and water are noncorrosive liquids of limited reactivity and the liquid temperature range is reasonably wide. This means that manipulations in liquid ammonia are not restricted by the attack on the containing vessels and a large range of substances are soluble without rapid solvolysis.