The Platinum Electrodes In A Conductivity Cell Are Platinized To?
Platinum electrodes are used in conductivity cells because they have a high electrical conductivity, they do not corrode or dissolve in water, and they can be made to be very pure. The process of platinizing platinum electrodes involves heating them under vacuum in stages to remove any oxide layers that may form on their surfaces. This treatment gives the platinum an extremely smooth surface that is highly resistant to corrosion by chemicals present in natural waters.
Addition of platinum to an aqueous solution containing aqueous sulfuric acid produces a colloidal suspension of platinum sulfate.
To produce colloidal platinum sulfate, you will need the following materials:
- A solution of 1 g/L of aqueous sulfuric acid in an Erlenmeyer flask.
- A platinum rod or wire about 2 cm long and 0.1 mm thick (the size is not important).
- Sulfuric acid (about 4 mL) from the fume hood. To avoid contamination, use only distilled water for this step!
The colloidal platinum sulfate is dried and the remaining water is removed by heating in an oven at 440 C.
The process is simple and can be done in a few hours. The result is an orange-red powder, which is the colloidal platinum sulfate. The purification of this product may require several steps, but it can be done at home using common laboratory equipment.
After drying, the platinum sulfate particles are placed in a vacuum vessel and heated under vacuum for about six hours until the particles become very small and round.
The platinum sulfate particles are placed in a vacuum vessel and heated under vacuum for about six hours until the particles become very small and round.
The resulting small, round particles are placed in a second vacuum chamber and heated under vacuum for another 24 hours at 400 C.
The resulting small, round particles are placed in a second vacuum chamber and heated under vacuum for another 24 hours at 400 C. This causes more of the platinum to bond onto the surface of each particle, forming larger grains that are visible to the naked eye.
After cooling to room temperature, the final product is stored in containers to prevent oxidation during use.
The electrolyte used in this type of cell is an aqueous solution of platinum sulfate (Pt(SO4)2). This compound is a good catalyst for the electrolysis of water and can be produced by adding platinum to an aqueous solution containing sulfuric acid.
The platinum electrode is platinized.
The platinum electrode is platinized. The platinum electrode is made of platinum, which is an expensive material. The platinum electrode is used in conductivity cells to measure the conductivity of solutions.