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 Δc Umo(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 Δc Hmo(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 Δf Hmo(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.