When an acid reacts with a base to produce a salt and water.
This type of reaction is called neutralization.
8.4 about neutralization reactions.
Let's examine the reaction of HCl (aq) and NaOH (aq) in details.
We learned in section 10.2 and section 10.3 that, in aqueous
solution, HCl and NaOH exist as ions in solution. The salt, NaCl, that forms
is soluble in water, therefore, it also exists as ions in solution. Therefore,
to describe the same reaction more precisely, we write the following reaction
revealing the ions that exist in the solution.
Careful inspection of the beakers will reveal that the
ions that have undergone reaction are the H+ and OH- ions.
The Na+ ions and Cl- ions remain unchanged before and
after the reaction. The Na+ ions and the Cl- ions are
called spectator ions.
If we leave out the spectator ions, and write the equation involving those ions
that participated in the reaction, we write the net
ionic equation of neutralization.
Since H+ ions
exist in solution as hydronium ions, H3O+, we can write the net
ionic equation in the following way.