South Pasadena
AP Chemistry
Name _________________________________
Period ___
Date ___/___/___
18
AcidBase Reactions
T I T R A T I O N C U R V E C A L C U L A T I O N S
Strong Acid – Strong Base Titrations
When a strong acid (such as HCl) and a
strong base (such as NaOH) are used for a
titration, the pH change looks like the
graph on the right.
You can calculate the
volume of base needed to reach the
equivalence point using the formula: V·M
=
V·M
or a line equation.
There are three situations in which you
determine pH.
initial strong acid concentration (this is
simply the –log[H
+
] which is based on the
[Acid].)
equivalence point (or endpoint) when
moles of OH
= moles of H
+
.
The pH is 7
(due to the autoionization of water.)
before and after the endpoint (calculate excess moles of H
+
or OH

, divide by the total
volume, and calculate the pH based on this value.)
Weak Acid – Strong Base Titrations
When a weak acid (such as HC
2
H
3
O
2
) is neutralized by a strong base (such as NaOH), the
graph varies in
two
ways:
the equivalence point is
You've reached the end of your free preview.
Want to read all 3 pages?
 Spring '08
 Kenney
 Chemistry, pH, AcidBase Reactions