Electrolysis of Molten Salt
Now let's consider the electrolysis of salts that are not in solution.
However, molten sodium chloride does. In this case we are dealing with molten sodium chloride. That simply means that we've taken sodium chloride and heated it up enough to where it is melted. When it melts, the sodium ions and the chloride ions can separate from one another somewhat, and they are free to move throughout the liquid.
Sodium chloride is not the only salt that can be used in this process. We could use any ionic compound that can be melted to free up the ions so that they can move.
An example is that aluminum metal can be generated from aluminum ores by this process. I would like you to consider the case of passing an electric current through molten aluminum oxide.
Some practical considerations to consider when actually making aluminum metal by this process include these. Are the electrodes really inert? How hot does aluminum oxide have to be to stay molten? Can people work around those temperatures? What voltage and current are needed to make this happen? And, of course, there are the economic and environmental issues of the cost and availability of large amounts of electricity and the price at which aluminum can be sold. If you know or meet someone who has worked in an aluminum plant, you might ask them how some of these practical considerations have been addressed.
E-mail instructor: Eden Francis
Clackamas Community College