NAME__________ __________ DATE _____PERIOD___
A.P. CHEMISTRY
MARCH 20. 2009
DIPROTIC ACID TITRAION CURVE
ABSTRACT:
PART ONE:
1) Present a researched titration curve for a weak diprotic acid, a
curve for citric acid would be best.
2) Label each part of the curve and explain the theory of the
following:
a. The weak acid before titration.
b. pKa 1 point
c. Ka 1 equivalence
d. pKa 2 point
e. Ka 2 equivalence
f. Base overshoot.
g. How to calculate the pH of any point on the curve ( buffer
zones for Ka 1 and Ka2 etc.)
h. Show how to calculate the Ka values if you know the pH
OR the volume of base added.
i. Show how the Henderson-Hasslebauch equation is adapted
for Ka2.
3) Plot your own titration curve with your lab data. CALCULATE
the pH for the points mentioned above and compare your answers
to the accepted values you researched.
4) Show how to get Ka 1 and 2 from the pH at the important
inflection points of the curve.