EDTA (ethylenediaminetetraacetic acid) is a chelating agent used to determine the concentration of metal ions in a sample. The EDTA method is based on the formation of a complex between EDTA and the metal ion that is being measured. The metal ion is titrated with EDTA until the metal ion is completely complexed. The endpoint of the titration is determined by a color change in the indicator solution.

Indicator Used in EDTA Method: Erio Chrome Black T

Erio Chrome Black T is the indicator used in the EDTA method. It is a synthetic dye that forms a complex with the metal ion. The complex changes color from red to blue at the endpoint of the titration. Erio Chrome Black T is used to determine the concentration of metal ions in a sample, including calcium, magnesium, and zinc.

Advantages of Erio Chrome Black T

There are several advantages of using Erio Chrome Black T as an indicator in the EDTA method:

1. It is highly selective for certain metal ions, including calcium, magnesium, and zinc.

2. It has a high molar absorptivity, which means that it is very sensitive to changes in concentration.

3. It has a wide pH range, which allows it to be used in a variety of applications.

4. It is stable and does not degrade over time, which ensures consistent results.

Conclusion

In conclusion, Erio Chrome Black T is the indicator used in the EDTA method. It is a highly selective and sensitive indicator that is widely used in the determination of metal ions in a sample. Its stability and wide pH range make it a reliable choice for many applications.