1. V. Acid-Base Titration
Titration is the process of adding a measured
volume of an acid or base of known molarity
(the standard solution) to an acid or base of
unknown molarity until neutralization occurs.
standard solution –
known molarity
(concentration)
An indicator is added to
the flask. It changes
color when neutralization
has occurred.
unknown
molarity

2. Remember:
acid base  water + salt
The net ionic equation of what really reacts is:
H OH  H2O
Neutralization occurs when the
number of moles of = number of moles of
H+ from the acid OH- from the base

3. molarity = moles solute
liters of soln.
molarity = moles
volume
molarity x vol. = moles

4. Remember:
acid base  water + salt
The net ionic equation of what really reacts is:
H OH  H2O
Neutralization occurs when the
number of moles of = number of moles of
H+ from the acid OH- from the base
(molarity x volume)acid = (molarity x volume)base
MAVA = MBVB (in Table T)

6. Remember:
acid base  water + salt
The net ionic equation of what really reacts is:
H OH  H2O
Neutralization occurs when the
number of moles of = number of moles of
H+ from the acid OH- from the base
(molarity x volume)acid = (molarity x volume)base
MAVA = MBVB (in Table T)
Volumes VA and VB must be in the same units (mL or L).

7. Ex. How many milliliters of 4. 00 M NaOH are required to neutralize 50
Ex. How many milliliters of 4.00 M NaOH are required to neutralize 50.0 milliliters of 2.00 M solution of HNO3?
MAVA = MBVB
(2.00 M)(50.0 mL) = (4.00 M) x
(2.00 M)(50.0 mL) = x
4.00 M
25 mL = x
Note: 2x the concentration  ½ as much needed

8. Ex. What is the molarity of an HCl solution if 30
Ex. What is the molarity of an HCl solution if 30. mL of the acid are needed to neutralize 10. mL of a 6.0 M NaOH solution?
MAVA = MBVB
x (30. mL) = (6.0 M)(10. mL)
x = (6.0 M)(10. mL)
30. mL
x = M
Note: 3x as much needed  1/3 the concentration

9. In the equation MAVA = MBVB,
MA means moles of H+/liter
1 M HCl yields (gives) 1 mole of H+/liter
2 M HCl yields 2 moles of H+/liter
Note: Diprotic acids yield twice as many H+/liter
1 M H2SO4 yields 2 moles of H+/liter
2 M H2SO4 yields 4 moles of H+/liter
And: MB means moles of OH-/liter
1 M NaOH yields 1 mole of OH-/liter
2 M NaOH yields 2 moles of OH-/liter
Note: Dihydroxy bases yield twice as many OH-/liter
1 M Ca(OH)2 yields 2 moles of OH- /liter
2 M Ca(OH)2 yields 4 moles of OH- /liter

10. Ex. What is the concentration of a sulfuric acid solution if 50
Ex. What is the concentration of a sulfuric acid solution if 50. mL of 0.40 M KOH are needed to neutralize 20. mL of the H2SO4 solution of unknown concentration?
MAVA = MBVB
x (20. mL) = (0.40 M)(50. mL)
x = (0.40 M)(50. mL)
20. mL
x = M
But H2SO4 is diprotic. Each molecule produces 2 H+ ions.
So the concentration only needs to be half as much:
true x = 1.0 M/2 =
0.50 M

11. Experi- mental design: A volume of known molarity
is added to a burette and its
initial volume is recorded.
The burette solution is titrated
into the flask solution until the
indicator changes color
The volume of burette
solution used is found
by subtracting initial and
final burette volumes
A known volume of unknown
molarity is measured and added
to the flask. Then an indicator
is added.

12. Ex. 75 mL of KOH of unknown concentration are
added to a flask and some indicator is added. The
burette contains 2.5 M HCl. Its initial volume reading
is 19 mL. The acid is slowly added until the indicator
changes color. The final burette volume is 61 mL.
Find the concentration (molarity) of the KOH.
MAVA = MBVB
(2.5 M)( mL) = x (75 mL)
(2.5 M)(42 mL) = x
75 mL
1.4 M = x