Electrolysis: Potassium Iodide (Molten)

Aim:

To find the oxidising and reducing agents of molten potassium iodide

Equipment:

1x U-tube made out of copper
A power supply
2x wires connecting power pack to carbon electrodes
2x carbon inert electrodes
Molten potassium iodide

Safety:

·         Wear protective gear such as thick boots, high durable safety glasses, lab coat and extremely durable gloves

·         Avoid contact with any molten potassium iodide because 680^oC > is a hot temperature

Procedure:

1.       Collect all equipment needed and make sure all safety precautions are done or set.

2.       Setup the apparatus the same way as the previous experiment (Electrolysis: Potassium Iodide (solution))

3.       Add molten potassium iodide to the copper U-tube and turn the power supply on.

4.       Observe and record all results.

Predicted Results:

Anode	Cathode
Collecting the gas and cooling it down allows us to see a purple/black coloured substance at room temperature	Silvery solid starts forming over the carbon electrode until there is no molten potassium iodide is left

Redox:

2I⁻ _(l) → I₂ _(g) + 2e⁻   Oxidising

2K⁺ _(l) + 2e⁻   → 2K_(s) Reducing

2I⁻ _(l) +2K⁺ _(l) → I₂ _(g) +2K_(s) Redox Equation

Discussion:

From the procedures of this experiment we can see right at the start that it is very dangerous because of many parameters. First of all, the temperature of the molten potassium iodide is extremely high. This is because of its ionic bond creating a very strong bond within the ions, and breaking these bonds requires high amount of energy such as heat. Therefore, because of these dangerous temperatures, safety equipment is compulsory.

Our group could not experiment this theory as the extreme temperatures, lack of equipment and lack of space all stopped us because of the high risks.

To conclude, we can say that this experiment is not practically possible to do in a school environment; however, this experiment is done on a massive scale in the mining industry allowing the separation of a compound to its elemental form such as potassium iodide.