What Drives this Type of
Reaction?
 Acid-base
neutralization reactions are a
special type of double replacement
• Remember that in a DR reaction, cations trade
places!
 We
will focus on reactants that include an
Arrhenius acid and an Arrhenius base
 As with precipitation reactions, products
can be predicted based on dissociated
ions in solution
Defined as a substance that yields H+ cations when dissolved in water
If acid dissociates completely (stays broken apart in water), it is
considered a strong acid
•
•
Examples of the dissociation of strong acids:
•
HCl aq → H + aq + Cl− aq
HNO3 aq → H + aq + NO−
3 (aq)
There are only 7 strong acids:
•
•

HCl






HNO3
H2SO4
HBr
HI
HClO3
HClO4
If an acid does not dissociate completely (only partly ionizes), then it is
considered weak
HC2H3O2(aq) ↔ H+(aq) + C2H3O2-(aq)
 Have
a pH less than 7
 Sour taste
 Turns blue litmus paper red
 React with carbonates to produce a salt,
water, and CO2
 React with active metals to produce
hydrogen gas
• Defined as a substance that yields OH- anions
when dissolved in water
• If base dissociates completely (stays broken
apart in water), it is considered a strong base
• Examples:
NaOH s → Na+ aq + OH − aq
KOH s → K + aq + OH − (aq)
 Taste
bitter
 Have a pH greater than 7
 Turns red litmus paper blue
 Feel slippery

As discussed, all acids and
bases do not ionize or
dissociate to the same extent
• This leads to the statement that
acids and bases are not all of
equal strength in producing H+
and OH- ions in solution

Acids and bases that
dissociate completely in
solution are able to conduct
electricity strongly
• A strong electrolyte

Acids and bases that only
partially dissociate conduct
electricity weakly
• A weak electrolyte
Chemical dyes whose colors are affected by acidic and
basic solutions are called acid-base indicators
• Each has its own particular pH or pH ranges over which
it changes color
•
•
Recall, Arrhenius acids form H+ ions and Arrhenius
bases form OH- ions when dissolved in water
•
•
•
These ions combine to form liquid water
The other product is a salt - an ionic compound
Example:
• Molecular equation:
HCl aq + NaOH aq → H2 O l + NaCl aq
• Complete ionic equation:
H+(aq) + Cl-(aq) +Na+(aq) + OH-(aq) Na+(aq) +Cl-(aq) + H2O(l)
 By eliminating the spectator ions, we discover the driving force behind the
neutralization of strong acid by a strong base
• Net ionic equation:
H+(aq) + OH-(aq) H2O(l)
•
So, the driving force for ALL neutralization reactions
is the formation of liquid water!
H + aq + OH − aq → H2 O l
•
The net ionic equation above applies for ALL acidbase neutralization reactions!
Acid
HCl
Base
+ NaOH
2HCl + Ca(OH)2
Salt
Water
NaCl + H2O
CaCl2 + H2O


Predict the products of the following acid-base
molecular equations. Then, balance the molecular
equation and label each substance with its physical
states. Finally, write the net ionic equations for each.
HCl ( )
+
Ba(OH)2 ( )
+
Al(OH)3 ( ) →
→
• Net Ionic –

HBr ( )
• Net Ionic –

Predict the products for the following molecular equations. Then, balance
the molecular equation and label each substance with its physical states.
Finally, write the net ionic equations for each. Then, identify each as
either an acid-base or precipitation reaction!
1. HNO3(aq) + KOH(aq) →
2. AgNO3(aq) + Na2CrO4(aq) →