Discussion Overview
The discussion revolves around the observed changes in potential within an electrochemical cell setup involving a phosphate buffer saline solution, a gold electrode, and a reference electrode (Ag/AgCl). Participants explore reasons for the potential drift over time and the factors influencing the measurements taken with a multimeter.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
Main Points Raised
- One participant notes that the potential measured by the multimeter decreases every few seconds and questions why this occurs despite stable temperature and pressure conditions.
- Another participant suggests that Ag/AgCl electrodes require time to equilibrate, recommending that the setup be left undisturbed for an hour to see if the drift subsides.
- A participant raises the possibility that the concentration difference between the phosphate buffer saline (1M) and the salt bridge solution (3M NaCl) could be contributing to the potential drift.
- Concerns are expressed about the multimeter drawing current from the cell, potentially causing polarization and affecting the potential readings. A suggestion is made to connect the meter only momentarily for readings.
- One participant reports improved readings after allowing the electrodes to equilibrate for an hour, but notes that the potential measured after disconnecting the meter is lower than before, raising questions about the cell's behavior when not connected.
Areas of Agreement / Disagreement
Participants express varying opinions on the causes of potential drift, with some suggesting time for equilibration and others pointing to the effects of current draw from the multimeter. The discussion remains unresolved regarding the exact reasons for the observed changes in potential.
Contextual Notes
Limitations include assumptions about the stability of temperature and pressure, the influence of different solution concentrations, and the effects of the multimeter's current draw on the electrochemical cell.
Who May Find This Useful
Researchers and students working with electrochemical cells, particularly those using Ag/AgCl electrodes, may find the insights and experiences shared in this discussion relevant to their own setups and measurements.