Azeotropic compositions

An azeotropic composition consisting essentially of:

• (A) 81 to 99 weight percent of an acyclic perfluorinated alkane selected from the group consisting of perfluorohexane and perfluoropentane;
• and
• (B) 1 to 19 weight percent of an acyclic ether solvent, which solvent is t-amyl methyl ether if the acyclic perfluorinated alkane is perfluorohexane, and t-butyl methyl ether if the perfluorinated acyclic alkane is perfluoropentane;
• such that the composition, when fractionally distilled, will yield a distillate fraction that is an azeotrope, the azeotrope:
• (i) consisting essentially of 90 weight percent acyclic perfluorinated alkane and 10 weight percent acyclic ether;
• and
• (ii) having a boiling point of 53.degree. C. at ambient pressure, when the acyclic perfluorinated alkane is perfluorohexane, or, when the acyclic perfluorinated alkane is perfluoropentane, a boiling point of 25.degree. C. at ambient pressure.