C-Na (Carbon-Sodium) system

The equilibrium process of C-Na (Carbon-Sodium) system is investigated. The Na 2C 2 solubility data was converted to unit carbon activity by a thermodynamic calculation using experimentally determined Gibbs energies of formation of Na 2C 2. The C 2Na 2 may be prepared by the reaction of Na with acetylene, either directly or in the liquid ammonia solution. The substance formed in liquid ammonia is C 2HNa, which, when heated in vacuo above 100 °C, yields C 2Na 2. C 60 may be prepared in an ac arc between graphite electrodes in subatmospheric Ar or He. The C 60 also is extracted from the smoke of carbon particles by an organic solvent.