CH 3 COOH(aq)NaOH(aq)88nNaCH 3 COO(aq)H 2 O()The total ionic equation for this reaction is
CH 3 COOH(aq)[Na(aq)OH(aq)]88n[Na(aq)CH 3 COO(aq)]H 2 O()Elimination of Nafrom both sides gives the net ionic equation
CH 3 COOH(aq)OH(aq)88nCH 3 COO(aq)H 2 O()In general terms, the reaction of a weak monoprotic acidwith a strong baseto form a
soluble saltmay be represented as
HA(aq)OH(aq)88nA(aq)H 2 O() (net ionic equation)EXAMPLE 10-1 Equations for Acid–Base Reactions
Write (a) formula unit, (b) total ionic, and (c) net ionic equations for the complete neutraliza-
tion of phosphoric acid, H 3 PO 4 , with potassium hydroxide, KOH.
Plan
(a) The salt produced in the reaction contains the cation of the base, K, and the PO 43 anion
of the acid. The salt is K 3 PO 4.
(b) H 3 PO 4 is a weak acid—it is not written in ionic form. KOH is a strong base, and so it is
written in ionic form. K 3 PO 4 is a soluble salt,and so it is written in ionic form.
(c) The spectator ions are canceled to give the net ionic equation.
Solution
(a) H 3 PO 4 (aq)3KOH(aq)88nK 3 PO 4 (aq)3H 2 O()
(b) H 3 PO 4 (aq)3[K(aq)OH(aq)]88n[3K(aq)PO 43 (aq)]3H 2 O()
(c) H 3 PO 4 (aq)3OH(aq)88nPO 43 (aq)3H 2 O()You should now work Exercise 58.
EXAMPLE 10-2 Equations for Acid–Base Reactions
Write (a) formula unit, (b) total ionic, and (c) net ionic equations for the neutralization of
aqueous ammonia with nitric acid.
Plan
(a) The salt produced in the reaction contains the cation of the base, NH 4 , and the anion of
the acid, NO 3 . The salt is NH 4 NO 3.
(b) HNO 3 is a strong acid—we write it in ionic form. Ammonia is a weak base. NH 4 NO 3 is
a soluble salt that is completely dissociated—we write it in ionic form.
(c) We cancel the spectator ions, NO 3 , and obtain the net ionic equation.
Solution
(a) HNO 3 (aq)NH 3 (aq)88nNH 4 NO 3 (aq)
(b) [H(aq)NO 3 (aq)]NH 3 (aq)88n[NH 4 (aq)NO 3 (aq)]
(c) H(aq)NH 3 (aq)88nNH 4 (aq)You should now work Exercise 60.
Monoprotic acids contain one, diprotic
acids contain two, and triprotic acids
contain three acidic (ionizable)
hydrogen atoms per formula unit.
Polyprotic acids (those that contain
more than one ionizable hydrogen
atom) are discussed in detail in
Chapter 18.When all the Hfrom the acid and all
the OHof the base have reacted, we
say that there has been complete
neutralization.10-8 Acid–Base Reactions in Aqueous Solutions 385Neutralization reactions of ammonia,
NH 3 , form salts but do not form
water.