抄録
The effect of water vapor pressure on the kinetics of the thermal dehydration of some formate hydrates was studied by means of isothermal gravimetry under various water vapor pressures from 6.7×10-2 to 1.33×103Pa. The rates of dehydrations of Zn, Y and Er formate dihydrates exhibited an unusual dependence upon the water vapor pressure; with increasing water vapor pressure the rates increased at first, passed through a maximum, and then decreased gradually to a constant values. These unusual phenomena were analogous to the Smith-Topley effect. On the other hand, the rates of dehydrations of Mg, Mn and Co formate dihydrates decreased with increasing water vapor pressure as was naturally expected from the equilibrium theory.
The mechanism of the unusual phenomena was discussed in correlation with the crystallinity of the dehydrated products.
