Is #H_3O^+# hard water? What occurs in an aqueous solution of acetic acid?
Here's what's going on.
First and foremost,
Hard water is simply water that has a high concentration of multivalent cations, which are cations that have charges greater than
When acetic acid,
SImply put, acetic acid is a stronger acid than water, so it will donate its acidic proton to a water molecule, which will act as a base and accept this proton.
The water molecule that accepts this proton will form the
Keep in mind that the reaction does not go to completion because acetic acid is a weak acid in an of itself, so an equilibrium will be established between the unionized and ionized forms
#overbrace("CH"_3"COOH"_text((aq]))^(color(green)("acts as an acid")) + overbrace("H"_2"O"_text((l]))^(color(blue)("acts as a base")) rightleftharpoons "CH"_3"COO"_text((aq])^(-) + "H"_3"O"_text((aq])^(+)#
In fact, the equilibrium lies to the left, meaning that more acetic acid molecules will not ionize in aqueous solution.
Because acetic acid is a weak acid, that will to some extent retain the proton bound to the oxygen.
Acetic acid undergoes the following equilibrium in water:
This is the normal behaviour for an acid, i.e. for the generalized acid,
The equilibrium constant,