Аннотация:At present, the production volumes of methanesulfonic acid (HSO3CH3) are about 50,000 tons peryear and it is predicted its further growth in particular due to the fact that recently it was found anenvironmentally friendly method of methanesulfonic acid production [1]. Nevertheless,information on the properties of methanesulfonic acid derivatives is presented fragmentary in theliterature. This work was carried out as a part of a project to study the thermodynamic propertiesof methanesulfonic acid salts (RFBR No.16-33-00958).Thermodynamic properties of calcium methanesulfonate are of interest for chemical industry andenvironmental science. Calcium methanesulfonate is applied as catalyst [2] and can be used asadditives to heavy fluids [3]. Calcium methanesulfonate is presented in the form of aerosols inatmosphere, which are responsible for the formation of clouds [4]. Methanesulfonic acid salts aredecomposed under the influence of microorganisms in soil [5] and are accumulated in glaciers [6].It is relevant to replenish databases by thermodynamic properties of methanesulfonic acidderivatives.In the present study molar heat capacity of calcium methanesulfonate Ca(SO3CH3)2 was measuredin the temperature range from 8 to 340 K by low-temperature vacuum adiabatic calorimetry. Theuncertainties of heat capacity determination were on average 0.2–0.3 %. Obtained values of heatcapacity were approximated by power polynomials. Heat capacity and the main thermodynamicfunctions (changes of enthalpy, entropy and Gibbs energy) of Ca(SO3CH3)2 in a solid state weretabulated as a function of temperature from 5 to 340 K.The enthalpy of Ca(SO3CH3)2 dissolution in water was determined at 298.15 K by means ofsolution calorimetry. The uncertainty of the enthalpy of dissolution was 0.1 %.On the basis of the experimental data, the standard entropy, enthalpy and Gibbs energy ofCa(SO3CH3)2 formation at 298.15 K were calculated.
