The partial molar heat contents of solutes in sulphuric acid at 25°C. An investigation of the self-dissociation of sulphuric acid

Abstract

Measurements are reported of the partial molar heat contents at 25" of potassium, ammonium, and barium hydrogen sulphates, acetic acid, and water, in solution in sulphuric acid in the region of suppression of the solvent self-dissociation. The thermal effects of adding water (hydroxoniurn hydrogen sulphate) to sulphuric acid already containing other hydrogen sulphates have also been investigated, and these measurements confirm the view of Gillespie, Hughes, and Ingold that water suppresses a form of dissociation that is not suppressed by other hydrogen sulphates. Standard free energy, heat, and entropy values have been calculated for the autoprotolytic and ionic dehydration forms of dissociation and have been shown to be consistent with accurate cryoscopic data.

Turbulent liquid flow down vertical walls

“…Jackson used the Froude number in the form lVFl = V/(SVdi (8) as a criterion for wave inception. When Equations (4) and (8) are combined, the Froude number can be expressed in terms of the Fanning friction factor as N F , = d2/f (9) Consequently Equation (7) can equally well be written in the form…”

“…Kirkbride measured the thicknesses of falling liquid films by means of direct contact with a micrometer (8). Fallah, Hunter, and Nash obtained average thicknesses from measurements of liquid holdup on vertical walls (3).…”

Solutions of Electrolytes

“…to 130°C., Ackermann (34) reports the dissociation constant of water and partial molal entropies and heat capacities of the ions. Kirkbride & Wyatt (144) have measured partial molar heat contents of several bisuifates, acetic acid, and water in sulfuric acid at 25°C. The data supports the existence of both autoprotolysis and ionic dehydration, sug gested earlier by Gillespie, Hughes & Ingold (145); molal dissociation con stants, 3.4 X 10-4 and 1.8 X 10-4 , respectively, and other thermodynamic functions are in good agreement with earlier cryoscopic work.…”