(JP6509101-W)      Azeotropic or azeotrope-like compsns. (I) consist of varying amts. of pentafluoro-ethane (II) and propane (III) or isobutane (IV). Specifically claimed are the following: a) contg. 65-99 wt.% (II) and 1-35 wt.% (III) and which boils at 25 deg.C at 226 psia; b) contg. 79.4 wt.% (II) and 20.5 wt.% (III) and which boils at (-14) deg.C at 75.6 psia; c) contg. 90-99 wt.% (II) and 1-10 wt.% (IV) and which boils at 25 deg.C at 195 psia; d) 98.3 wt.% (II) and 1.7 wt.% (IV) and which boils at 11.2 deg.C at 135.9 psia; e) contg. effective amts. of (II) and (III) or (IV) such that its dew point temp. differs from its bubble point temp. by 1 deg.C or less; and f) contg. effective amounts of (II) and (III) or (IV) such that its vapour pressure differs by 10% or less from the vapour pressure when 50 wt.% of the compsn. is removed.    Also claimed are processes for (i) producing refrigeration by condensing and evaporating (I); (ii) producing heat by condensing and evaporating (I); (iii) preparing a polymer foam using (I) as a blowing agent; and (iv) preparing an aerosol formulation by combining (I) with the active aerosol ingredients.    USE/ADVANTAGE -   (I) are environmentally safe substitutes for halogenated chloro-fluoro-carbons.    (EP592555-B2)      Azeotropic or azeotrope-like compsns. (I) consist of varying amts. of pentafluoro-ethane (II) and propane (III) or isobutane (IV). Specifically claimed are the following: a) contg. 65-99 wt.% (II) and 1-35 wt.% (III) and which boils at 25 deg.C at 226 psia; b) contg. 79.4 wt.% (II) and 20.5 wt.% (III) and which boils at (-14) deg.C at 75.6 psia; c) contg. 90-99 wt.% (II) and 1-10 wt.% (IV) and which boils at 25 deg.C at 195 psia; d) 98.3 wt.% (II) and 1.7 wt.% (IV) and which boils at 11.2 deg.C at 135.9 psia; e) contg. effective amts. of (II) and (III) or (IV) such that its dew point temp. differs from its bubble point temp. by 1 deg.C or less; and f) contg. effective amounts of (II) and (III) or (IV) such that its vapour pressure differs by 10% or less from the vapour pressure when 50 wt.% of the compsn. is removed.    Also claimed are processes for (i) producing refrigeration by condensing and evaporating (I); (ii) producing heat by condensing and evaporating (I); (iii) preparing a polymer foam using (I) as a blowing agent; and (iv) preparing an aerosol formulation by combining (I) with the active aerosol ingredients.    USE/ADVANTAGE -   (I) are environmentally safe substitutes for halogenated chloro-fluoro-carbons. They do not deplete ozonewhi