Investigation of Acid-Base Indicator Property of Plumbagin from Plumbago zeylanica Linn

Table 9

Colour of the indicator and solvent in different solutions on evaluation of specificity.

	Plumbagin			Methanol
	NaOH (analyte)/HCl (titrant)	HCl (analyte)/NaOH (titrant)	CH3COOH (analyte)/NaOH (titrant)	NaOH (analyte)/HCl (titrant)	HCl (analyte)/NaOH (titrant)	CH3COOH (analyte)/NaOH (titrant)
Colour of the indicator before titration	Pink	Yellow	Yellow	Colourless	Colourless	Colourless
Colour of the indicator after titration	Yellow	Pink	Pink	Colourless	Colourless	Colourless