Solution Formation and Chemical Reactions

In discussing solutions, we must be careful to distinguish the physical process of solution formation from chemical reactions that lead to a solution. For example, nickel metal dissolves on contact with hydrochloric acid solution because the following reaction occurs  

In this instance the resultant solution is not that of the Ni metal but rather its salt NiCl2. If the solution is evaporated to dryness, NiCl2 6 H20(s) is recovered ( FIGURE 13.6). When NaCl(s) is dissolved in water, on the other hand, no chemical reaction occurs. If the solution is evaporated to dryness, NaCl is recovered. Our focus throughout this chapter is on solutions from which the solute can be recovered unchanged from the solution. 

Nickel reacts with hydrochloric acid, forming NiCl2(fl ) and H2(g). The solution is of NiCl2, not Ni metal 

NiQ2 6H20(s) remains when solvent evaporated 

A FIGURE 13.6 The reaction between nickel metal and hydrochloric add is not a simple dissolution. 

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