Thermochimica Acta, Vol.308, No.1-2, 165-170, 1998
Measurement of equilibrium water vapor pressures for the thermal dehydrations of some formate dihydrates by means of the transpiration method
The equilibrium water vapor pressures, P-H2O for the thermal dehydrations of some formate dihydrates, M(HCO2)(2).2H(2)O, where M is Mg, Mn, Co, Ni and Zn, were measured by means of the transpiration method using a laboratory-made apparatus. These hydrates have a monoclinic isomorphous crystal structure with a space group, P2(1)/C. The thermodynamic data such as Delta G, Delta H and Delta S for the dehydration were derived from the P-H2O and correlated to the crystal structures of these hydrates. Although the values of Delta H were expected to increase in the order of the hydrates of Mn