Standard enthalpy of formation of (NO2)2[NiF6](cr)

The enthalpies of interactions of (NO2)2[NiF6](cr) with water and aqueous KOH, enthalpies of solution of KF(cr) in dilute aqueous solutions of KNO3 and KOH, and enthalpy of mixing of solutions of NiF2, HNO3, and HF were measured at 298.15 K using isothermic-shell calorimeters. Based on the obtained data and values in the literature, the standard enthalpy of formation of the compound under study was determined by two independent methods: Δf H°(NO2)2[NiF6](cr) = −1099 ± 9 kJ/mol.