Abstract
Thermodynamics and thermal properties of clathrate hydrates, including semiclathrate hydrates of tetraalkylammonium salts as well as ordinary gas hydrates, have been reviewed.
For gas hydrates, the following topics have been discussed: (i) determination of a hydration number from the temperature dependence of the dissociation pressure; (ii) heat of encagement of guest molecules; and (iii) heat of formation of a vacant water cage from ice I.
For semiclathrate hydrates ((n-C4H9)4NF (or Cl)·30H2O and (i-C5H11)4NF (or Cl)·39H2O), such topics as (i) direct calorimetric determination of the heat of solution in water and of the heat of fusion of the hydrate solid and (ii) the calculation of their heats of solution in saturated aqueous solutions from temperature dependence of their solubilities in water, have also been discussed.
