 Neutralization of the strong base sodium hydroxide and the strong acid hydrochloric acid also form solutions of sodium chloride, reversing the energy-absorbing process of electrolysis that make both sodium hydroxide and hydrochloric acid more costly than sodium chloride—and requires the evaporation of water from the solution, which is not practical.Likewise it forms from many reactions involving solutes that allow sodium chloride as the remaining solute in solution after a reaction between a metallic chloride (most are soluble)
and such a salt as sodium carbonate (one of few water-soluble carbonates) as an insoluble carbonate.Thus the addition of ferrous chloride into a solution of sodium carbonate or sodium carbonate leads to the precipitation of ferrous carbonate with sodium chloride remaining in the solution.