In an EDTA titration using Eriochrome Black T indicator, the pink color indicates the presence of free metal ions, such as calcium or magnesium, which form complexes with the indicator. As EDTA is added, it binds to these metal ions more strongly than the indicator does, causing the indicator to release the metal and change color. At the endpoint, when all the metal ions have reacted with EDTA, the indicator turns blue due to its transition to a form that is free of metal ions, indicating that the titration is complete.
Prince was born February 13, 1997. Paris was born April 3, 1998 and Prince II or Blanket was born February 2002. His day of birth is unknown but some say it's the 21st.
Replacement Titration: In this method the metal, which is to be analyzed, displaces quantitatively the metal from the complex. When direct or back titrations do not give sharp end points, the metal may be determined by the displacement of an equivalent amount of Mg or Zn from a less stable EDTA complex. Mn+2 + Mg EDTA---> 2 Mg+2 + Mn EDTA-2 Mn displaces Mg from Mn EDTA solution. The freed Mg metal is then directly titrated with a standard EDTA solution. In this method, excess quantity of Mg EDTA chelate is added to Mn solution. Mn quantitatively displaces Mg from Mg EDTA chelate. This displacement takes place because Mn forms a more stable complex with EDTA. By this method Ca, Pb, Hg may be determined using Eriochrome blackT indicator.