Heat capacity of MgCl2 center dot 6H(2)O was determined in temperature range from 298.15 to 401.15 K. Polynomial function was used to fit temperature dependence of heat capacity up to 371.15 K and corresponding thermodynamic functions (H-T-H-298.15, S-T-S-298.15, G(T)-G(298.15)) were calculated. Thermal stability test(50 heating/cooling cycles) of pure MgCl2 center dot 6H(2)O shows supercooling about 37K, thus some nucleating agents were tested. Addition of SrCO3 (1 wt%) and Sr(OH)(2) (0.5 wt%) almost fully suppresses the supercooling while addition of Mg(OH)(2) decreases supercooling by 19K. (C) 2012 Elsevier B.V. All rights reserved.