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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