Use
Sodium hydride belongs to ionic crystals, salt compounds in which the hydrogen is negative monovalent ions. When heating, it is unstable, decomposition without melting, hydrolysis reaction of sodium hydride with water to prepare sodium hydroxide and hydrogen.
Pure sodium hydride is silver needle-like crystals, commercially available sodium hydride merchandise usually is subtle gray crystalline powder, the proportion of sodium hydride is 25% to 50% dispersed in oil. The relative density is 0.92. Sodium hydride is crystalline rock salt type structure (lattice constant a = 0.488nm), and as lithium hydride in ionic crystalline, hydrogen ion is existent in anion form. Heat of formation is 69.5kJ mol-1, at the high temperature of 800 ℃, it decomposes into metallic sodium and hydrogen; decomposes explosively in water; reacts violently with lower alcohols;dissolves in molten sodium and molten sodium hydroxide; insoluble in liquid ammonia, benzene, carbon tetrachloride and carbon disulfide.