Topic: Neutralization Reaction
Do Now:
Neutralization Reactions
• Acid + Base → Salt + Water
HX(aq) + MOH(aq) → MX(aq) +H2O(l)
DR rxn
Acid-Base Titration
• A procedure used in order to determine the unknown
molarity of an acid or base
• MAVA = MBVB
• (molarity of acid)(volume of acid) = (molarity of base)(volume of base)
•
You will know 3 out of the 4 variable
• Standard solution slowly added to unknown solution
• As solutions mix:
– neutralization reaction occurs
• Eventually:
– enough standard solution is added to neutralize the
unknown solution
pH changes during neutralization
• Start with an acid pH < 7
• Add a base pH 
• At neutralization pH = 7
• Start with a base pH > 7
• Add an acid pH 
• At neutralization pH = 7
• acid-base indicator needed
• WHY?
• Usually use phenolphalein
• WHY?
When pH = 7
called equivalence point
[H+] = [OH-]
Titration
• End-point = point at which indicator
changes color
– if indicator chosen correctly:
• end-point very close to equivalence point
MH VH = MOH VOH
+1
+1
-1
-1
• If you titrate H2SO4 and NaOH
2H+
1OH+-
Titration Problem #1
• In a titration of 40.0 mL of a
nitric acid solution, the end point
is reached when 35.0mL of
0.100M NaOH is added
Calculate the concentration of the
nitric acid solution
HNO3 + NaOH  H2O + NaNO3
Variables
• # of H’s = 1
• Ma = ?
• Va = 40.0 mL
• # of OH’s = 1
• Mb = 0.100 M
• Vb = 35.0 mL
(1)(X) (40.0 mL) = (0.100 M )(35.0mL)(1)
X = 0.875 M HNO3
Titration Problem #2
• What is the concentration of a
hydrochloric acid solution if 50.0 mL
of a 0.250M KOH solution is needed
to neutralize 20.0mL of the HCl
solution of unknown concentration?
KOH + HCl  H2O + KCl
(1)(X)(20.0 mL) = (0.250 M) (50.0 mL)(1)
X = 0.625 M HCl
Titration Problem #3
• What is the concentration of a
sulfuric acid solution if 50.0mL of a
0.25 M KOH solution is needed to
neutralize 20.0mL of the H2SO4
solution of unknown concentration?
H2SO4 + 2 KOH  2 H2O + K2SO4
(2)(X)(20.0ml) = (0.25M)(50.0ml)(1)
X = 0.3125 M H2SO4(sulfuric acid)