KI Electrode Testing
We continued with making an I- ISE to determine concentration of iodide in solution.
Procedure
- Ag/AgCl Electrode:
- The plastic covering was removed, and stored in the 3 M NaCl solution
- Double-Junction:
- Diluted saturated KNO3 was added to the double junction cell
- Silver Wire:
- A piece was cut and placed in KI/KNO3 solution and electrolyzed
- KI Standard Curve:
- The Ag/AgCl electrode was placed in the double-junction electrode. The Ag/AgCl electrode was attached to the multimeter
- The silver wire was attached directly to the alligator clip
- KI solutions were tested for potential
Results
[KI], mM
|
ln of KI
|
Potential, mV
|
50 |
3.912023005 |
-278.3
|
5 |
1.609437912 |
-223
|
0.5 |
-0.693147181 |
-161.8
|
0.05 |
-2.995732274 |
-105.1
|
0.005 |
-5.298317367 |
-70
|
|