Studies of gas-solid equilibria.—Part II. Pressure-concentration equilibria between and ( <i>a</i> ) ferric oxide gel, ( <i>b</i> ) silica gel, directly determined under isothermal conditions

Abstract

Abstract In Part I of this work the pressure-temperature equilibria between these same substances were accurately determined in a number of sealed systems of known and unalterable composition; pressure-concentration isothermals derived from these measurements indicated that there was a profound difference between the adsorptive processes of the analogous ferric oxide and silica gels. In this Part of the work the pressure-concentration equilibria of the same systems (using specimens from the same batches of the gels) have been investigated under isothermal conditions and with known concentrations of benzene varying from zero up to saturation. The effects, on known weights of the gels, of the isothermal addition and the isothermal withdrawal of known quantities of benzene have been determined and “ascending” and “descending” pressure-concentration isothermals have been drawn from these direct measure­ments.