why we use phenolphthalein indicator in the determination of the strenght of NAOH by using standard oxalic acid why not the others indicator?
2 answers
What others specifically. The general answer is that phenolphthalein changes color more nearly at the equivalence point for your titration than the other indicators you might have available.
In this titration the end point will occur at a pH hihger then 7 since it involves a strong base and weak acid.(therefore the salt CH3COONA will be basic in nature).The point is 8,5-9.00 and therefore the most suitable indicator will be phenolphtalein since the end points range is contained along the pH in which the indicator(phenolphtalein) is active.
2 answers