Titration of Weak Acids with Strong Bases

acids

formic acid

acetic acid

hydrofluoric acid

fluoroacetic acid

dinitromethane

malonaldehyde

acid concentration

acid volume

base concentration

Weak monoprotic acids can be neutralized in the presence of a strong base (such as sodium hydroxide) to form a buffered solution between the excess acid and the newly formed sodium salt of the conjugate base. As base is added, but before the acid is completely neutralized, the

pH

of the solution can be calculated using the Henderson–Hasselbalch equation:

pH=

pK

a

+log

[salt]

[acid]

, where

pK

a

is the negative log of the acid dissociation constant and

[salt]

and

[acid]

are concentrations in moles per liter. After the neutralization, the

pH

is determined by the amount of excess base present. The volume of base required to reach the equivalence point (point of inflection) is determined by three variables: the concentration and volume of acid present and the concentration of base being added.