Abstract:

As the voltage standard used for a very long time, Weston standard cells have made great contributions to electrochemistry. They also appear in the college-level physical chemistry experiment "Reversible cell potential measurement of electrochemical cells using the compensation method". However, the content on standard cells in physical chemistry textbooks is relatively brief and students are prone to confusing amalgam and metal electrodes. Several aspects of standard cells are presented in this paper. The reactions occurring at the negative and positive electrode, as well as the overall reaction, the factors influencing the reversible cell potential have been analyzed using the Nernst equation. The stability of the reversible cell potential has been discussed in terms of the cell temperature coefficient. Moreover, the reversibility and role of amalgam electrodes have been clarified. The effect of the selection of standard cells on the measurement results has also been discussed. These make up for the shortcomings in teaching and teaching materials, and may provide reference for both peer teaching and student learning.

Key words: Standard cells, Weston cells, Reversible cell potential, Amalgam electrodes, Standard electrode potential