Lattice potential energy and standard molar enthalpy in the formation of 1–dodecylamine hydrobromide (1–C₁₂H₂₅NH₃·Br)(s)

This paper reports that 1-dodecylamine hydrobromide (1–C₁₂H₂₅NH₃·Br)(s) has been synthesized using the liquid phase reaction method. The lattice potential energy of the compound 1–C₁₂H₂₅NH₃·Br and the ionic volume and radius of the 1–C₁₂H₂₅NH₃⁺ cation are obtained from the crystallographic data and other auxiliary thermodynamic data. The constant-volume energy of combustion of 1–C₁₂H₂₅NH₃·Br(s) is measured to be Δ_cU_m^o(1–C₁₂H₂₅NH₃·Br, s) =–(7369.03±3.28) kJ·mol^-1 by means of an RBC-II precision rotating-bomb combustion calorimeter at T=(298.15±0.001) K. The standard molar enthalpy of combustion of the compound is derived to be Δ_cH_m^o(1–C₁₂H₂₅NH₃·Br, s)=–(7384.52±3.28) kJ·mol ^{- 1} from the constant-volume energy of combustion. The standard molar enthalpy of formation of the compound is calculated to be Δ_fH_m^o(1–C₁₂H₂₅NH₃·Br, s)=–(1317.86±3.67) kJ·mol^-1 from the standard molar enthalpy of combustion of the title compound and other auxiliary thermodynamic quantities through a thermochemical cycle.