Thermodynamic properties of vitamin B2

•Temperature dependence of heat capacity of vitamin B2 has been measured by precision adiabatic vacuum calorimetry.•The thermodynamic functions of the vitamin B2 have been determined for the range from T → 0 to 322 K.•The energy of combustion of the riboflavin has been measured at 298.15 K.•The enthalpy of combustion ΔcH° and the thermodynamic parameters ΔfH°, ΔfS°, ΔfG° have been calculated.

In the present work temperature dependence of heat capacity of vitamin B2 (riboflavin) has been measured for the first time in the range from 6 to 322 K by precision adiabatic vacuum calorimetry. Based on the experimental data, the thermodynamic functions of the vitamin B2, namely, the heat capacity, enthalpy H°(T) − H°(0), entropy S°(T) − S°(0) and Gibbs function G°(T) − H°(0) have been determined for the range from T → 0 to 322 K. The value of the fractal dimension D in the function of multifractal generalization of Debye's theory of the heat capacity of solids was estimated and the character of heterodynamics of structure was detected. In a calorimeter with a static bomb and an isothermal shield, the energy of combustion of the riboflavin has been measured at 298.15 K. The enthalpy of combustion ΔcH° and the thermodynamic parameters ΔfH°, ΔfS°, ΔfG° and of reaction of formation of the riboflavin from simple substances at T = 298.15 K and p = 0.1 MPa have been calculated.

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