The description of my problem is as follows:
I will like to find out how can I obtain a mathematical equation which could give me a surface plot of the current output as a function of both concentration and time from an electrochemical cell which uses the following redox equation:
O2 + 2Pb -> 2PbO
I have the following information:
- Mass of Pb - 10g
- A fixed concentration of oxygen gas - 20.9% over volume of air in room
- Unlimited supply of oxygen
- The gas is supplied at constant room temperature and pressure (25 degree Celcius and 1 atm)
Tentatively, my plan was to use Farday's Law of Electrolysis (https://en.wikipedia.org/wiki/Faraday%27s_laws_of_electrolysis) to calculate the current which flows as a result of the transfer of electrons from the redox reaction. My hypothesis is:
- The magnitude of the current generated by the following reaction will be proportional to the rate of oxygen consumption.
- The magnitude of the current generated will decrease over time as the rate of reaction decrease (from the decrease in concentration of Pb).
My problem is that the plot I obtained shows me that the current vs time relationship is a reciprocal one under fixed concentration of oxygen gas. This does not agree with the experimental results I obtained which shows that current output is steady and starts decreasing after a long period of time (a few months at least). Can someone help point out my the flaw in my argument? What should I do instead to obtain the plot I described?