The enthalpies of reactions in water of solid Ba(AuF6)2*4KrF2 and Ba(AuF6)2weremeasuredat298.2 Kusinganairtightliguidisotermal calorimeter. These enthalpies were used to obtain an alternate set of formation standard enthalpies for these compounds. The analogous to these measurings for AuF5 and MAuF6 (M=Na, K, Rb) and also AuF3 were conducted earlier. Recommendedvalues for AH"fzg8 mentioned solid fluorides are: AuF5= -413.2+5; NaAuF6= -1094.5k6.5; KAuF6= -1158.8k6.5; RbAuF6= -1145.2k6.5; AuF3= -473.4+5 kJ.mole-'. For AHofzg8 AUK was decided the value -433k6.5 kJ.mole'l. All compounds were prepared by fluorination of gold in KrF2 in solutions in HF (Kel-F reactor). Ba(AUF6)2.4KrF2 was prepared in conditions of a large excess of KrF2. It is interesting to notethatthe reactionAuF5 inwater and aqueous sodium hydroxide (0.05 N) went to precipitation of metallic gold, for example: AuF5 + 3.475H20= 0.35Au(,) + O.~~AU(OH)~(~) + 5HF(sol) + O.7625O2(g) llH298 = -491.9+1.6 kJ.mole-l The separate measurements gave values of -2442f15 and -3132f15 kJ.mole-l for AHofzg8 B~(AuF~)~ and Ba(AuF6)2*KrF2 respectively, yielding. Ba(AUF6)2 + 8H2O = BaF2 s) + ZAu(OH)3(,) + lOHF(,,l) + OZ(~) AH 298 = -729f6 kJ.mole' I ~(AUF6)2*4~F2+12H20=~F2(s) +ZAU(OH)~(~) +18HF(sol) +30~(~) +4Kr(g) AH 298 = -1548+10 kJ.mole-' The reaction enthalpy of the process AuF3(,) + F2(g) = AuF~(~) was estimated. AuF5 was synthesised by this reaction.