The kinetic characteristics (the rates of decomposition J and activati
on energies E-a) of thermal dehydroxylation of Mg(OH)(2), reported in
a number of available publications, have been analysed with the suppos
ition of dissociative evaporation of Mg(OH)(2) in the form of MgO and
H2O molecules. Despite the considerable differences in the measurement
conditions, the experimental values of J and E-a have been found to b
e in agreement with theoretical calculations. The calculations took in
to account the self-cooling effect, the depressing effect of external
water vapor on the decomposition rate, and partial transfer of the ene
rgy released in the condensation of MgO(g) to the reactant. The agreem
ent between the calculated and experimental data confirms the proposed
mechanism of decomposition. (C) 1998 Elsevier Science B.V.