Soluble salt

A soluble salt dissolves in water. To prepare one, an acid can be reacted with a suitable solid that supplies the salt's positive metal ion. The insoluble solid may be a metal, metal oxide, metal hydroxide or metal carbonate, although the AQA required practical specifically uses an insoluble oxide or carbonate.

A soluble salt can be prepared by reacting an acid with a suitable insoluble reactant, such as a metal oxide, metal hydroxide or metal carbonate. Although the starting reactant is insoluble, the salt produced must dissolve in the water present to make a salt solution.

An insoluble carbonate can also react with acid to make a soluble salt; in that case carbon dioxide is produced as well.