Natural Plant Extracts as Acid-Base Indicator and Determination of Their pKa Value

Table 1

Added volumes of 0.1 M Na₂HPO₄ solution and 0.1 M KH₂PO₄ solution.

Flask no.	KH2PO4 (mL)	Na2HPO4 (mL)
1	10.0	0.0
2	20.0	1.0
3	10.0	2.0
4	20.0	10.0
5	10.0	10.0
6	10.0	20.0
7	2.0	10.0
8	2.0	20.0
9	1.0	20.0
10	0.0	10.0