Thermodynamics of hydrochloric acid in (1-propanol+water) from electromotive-force measurements

The standard electromotive force of the cell: PtH₂(g)|HCl(m) in solvent |AgCl|Ag has been determined at 9 different temperatures ranging from 288.15 to 328.15 K in 20 (propan-1-ol+water) mixtures covering the whole range of solvent composition, by an extrapolation method making use of the extended terms of the Debye-Hückel theory. In solvents of high alcohol content, where the dielectric constant is small, it was necessary to correct for ion-pair formation. The temperature variation of the standard e.m.f. was used to calculate the standard thermodynamic functions for the cell reaction, the primary medium effects of various solvents upon HCl, and the standard quantities for the transfer of HCl from the standard state in water to the standard states in each other solvent. The significance of the transfer functions is discussed in relation to the acid-base strength, as well as the structural features of the solvents.