Electrochemical Calorimetry: IV . Measurement of the Reversible Heat Effect Attending the Passage of an Electric Current Across a Liquid Junction

Abstract

Measurements of the temperature changes resulting from the passage of current across the interface of two electrolytes were made at various distances from the junction so as to yield a temperature profile of the effect. The total heat effect was calculated from the area under the curve of the temperature profile. The coefficient obtained by dividing the total heat effect by the charge is reported as a voltage-equivalent. The following values were obtained for three systems of electrolytes and are probably correct to within about 7 mv: 0.04M hydrochloric acid and 0.4M hydrochloric acid, 30 mv; 0.90M hydrochloric acid and 3.0M potassium chloride, 80 mv; 1.15M hydrochloric acid and 1.21M lithium chloride, 80 mv. A hypothesis is advanced to relate the voltage‐equivalent of the heat effects to the diffusion liquid junction potentials and to the Peltier effect.