B22 Reactions of Sodium with Liquid Ammonia
Sodium dissolves in liquid ammonia to form a blue solution characteristic of a solvated electron in liquid ammonia. When the blue solution evaporates, a bronze metallic ring is observed at a concentration of about 1 mole sodium/6 to 10 moles ammonia. The reaction is run a second time with a bit of iron(III) oxide which catalyzes the reduction of ammonia to sodium amide and hydrogen. Sodium amide, a strong base, is frequently used as a reagent in nonaqueous reactions.
Na + (x+y) NH3 --> Na(NH3)x+ + e-(NH3)y (blue)
2 NH3 + 2 Na (Fe2O3(rust) catalyst) --> 2 NaNH2 + H2
G. P. Pass and H. Sutcliffe,"Practical Inorganic Chemistry",Chapman and Hall LTD., London,Great Britain, (1968).