B22 Reactions of Sodium with Liquid Ammonia

Description
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.

Equation
Na + (x+y) NH₃ --> Na(NH₃)_x⁺ + e^-(NH₃)_y(blue)

2 NH₃ + 2 Na (Fe₂O₃(rust) catalyst) --> 2 NaNH₂ + H₂

Reference
G. P. Pass and H. Sutcliffe,"Practical Inorganic Chemistry",Chapman and Hall LTD., London,Great Britain, (1968).