Abstract:

Expanding upon the "Basic Physical Chemistry Laboratory" module focused on the measurement of primary battery electromotive force (EMF), this paper introduces a novel experimental design. The design incorporates the often-neglected liquid junction potential, investigating its relationship with reversible battery EMF and the total EMF of the primary battery. The revised apparatus is cost-effective, straightforward, and offers stable and reproducible measurements for liquid junction potential. This improved experiment provides a more comprehensive and accurate representation of the components contributing to the total EMF of the primary battery, transcending the limitations of merely measuring reversible battery EMF. As a result, the experiment aids students in forming a well-rounded and accurate understanding of primary batteries and the underlying principles of electrochemistry. Furthermore, the measured liquid junction potential is applicable in calculating ion transference numbers, allowing for the integration of this advanced concept into the curriculum and thereby bolstering students' comprehensive skill set.

Key words: Liquid junction potential, Reversible battery electric potential, Semi-permeable membrane