Complexometric titration is used for estimation of amount of total hardness in water. It is widely used in pharmaceutical industry to determine metal concentration in drugs. Titanium dioxide is used in many cosmetic products. This can be analysed by complexometric titration.

A small amount of xylenol orange is added initially to the cobalt solution and it forms a complex with some of the Co2+. ... As the xylenol orange loses the metal ion, its color changes. Obviously, the indicator must not bind the metal ion as strongly as the complexing agent (EDTA) used for the titration.

Xylenol orange is an organic reagent, most commonly used as a tetrasodium salt as an indicator for metal titrations. When used for metal titrations, it will appear red in the titrand and become yellow once it reaches its endpoint.

XYLENOL ORANGE AR