What is the effect of using a hydrated solution as a electrolyte in a voltaic cell compared to a molten solution?
I read that heavier the hydrated ion, the lesser its mobility and hence lower conductivity.. or something. Please help!
The reason a voltaic cell works is the electrons from one strip of metal are transferred through the solution to the other strip of metal. Of course, the two strips of metal are connected by a conducting wire across the top of the cell, completing the electrical circuit. When thinking about the physical conditions of the conducting solution, we need something that will conduct the free exchange of electrons. A hydrated solution offers the dissociation ease that would encourage the exchange and conduction of electrons. A molten solution would tend to be more dense, which would tend to have more difficulty in the dissociation phase. So the hydrated solution would be better suited in this dissociation activity, providing an electrical "superhighway" through which electrons may freely be transferred from one metal strip to another. Another problem with a molten solution would be the ability to keep the solution molten. Most are solids at room temperature, which would not be conducive to the free exchange of electrons.