Heats of adsorption of ammonia and the three methylamines on silica gel

The object of this investigation was the determination of the heats of adsorption of ammonia and the three methylamines on silica gel of different mesh sizes at 25°C. and 40°C. The heats of adsorption of the methylamines on any adsorbent are not recorded in the literature, but that of ammonia on charcoal has been determined by Keyes and Marshall, by Magnus and Kratz, by Titoff, and by other workers. Its heat of adsorption on silica gel has been determined by Magnus and Kieffer. Since a knowledge of these data, along with a knowledge of the physical properties and thermodynamic properties, would be necessary for the design of an adsorption refrigerator using one of these substances as the refrigerant; and since a knowledge of the heats of adsorption of the members of this series of compounds might throw some light on their molecular structures and on the nature of adsorption, it was deemed advisable to undertake this investigation