That the dissolution is does not in

That the dissolution is does not involve a chemical change in the metal is indicated by the fact that
evaporation of the solutions regenerates the metal. If the product is not placed under thermal stress,
the metal can be recovered as a solvate having the formula M(NH 3 ) 6 . Moreover, the solutions have
densities that are lower than the solvent alone. It is clear that some expansion of the liquid occurs
when the metal dissolves. In appearance, all of the solutions are blue when dilute, but are bronze
colored when more concentrated than approximately 1 M. The solutions exhibit conductivity that
is higher than that of a 1:1 electrolyte. The conductivity decreases as the concentration of the metal
increases, but the conductivity of concentrated solutions is characteristic of metals. An additional
anomaly is that the solutions are paramagnetic, but the magnetic susceptibility decreases for concentrated
solutions. The magnitude of the magnetic susceptibility is in agreement with there being one
free electron produced by each metal atom. These are the facts that must be explained by any successful
model for these solutions.