Electrochemical studies at low temperatures, XI.: A study on the Cu|Cu(NO3)2H2O|Cu electrochemical thermocouple

Investigating the thermo-electrochemical properties of non-isothermal cells we have found that the values of thermo-electromotive-forces (E) above freezing point of the solution show a linear dependence on temperature. At temperatures below freezing points, in the interval of concentration of the Cu(NO3)(2), when the frozen out solid phase consits of ice, the values of E are increasing in consequence of the increase in Cu(NO3)(2) concentration of the solutions. On the other hand, when the solid phase at the freezing consists of Cu(NO3)(2) X H2O, as a result of the decrease in the Cu(NO3)(2) concentration, in the solutions the values of E will decrease. At temperatures below freezing points the values of E measured between poles of the cells beside the thermo electromotiveforce include the potential differences caused by the concentration unequalities of the two half-cells as well. The finding that the slopes of the E - Delta T lines (E') are increased by increasing the Cu(NO3)(2) activity suggests that the potential of the thermodiffusion may be approximately independent of the activity of the solute, and that the course of the E' approximate to f (lga(+/-)) function call probably be explained by the concentration dependence of the Galvani-potential.