Question

Complexometric titration indicators Except

• A. Mordant black - II
• B. Ferroin
• C. Catechol violet
• D. Xylene orange

Hint:

Remember, indicators for complexometric titrations form metal complexes; Ferroin is a redox indicator, not suitable for this purpose.

Answer 1

The Correct Option is B

- Complexometric titrations involve the use of indicators that form colored complexes with metal ions, helping to visually detect the endpoint.
- Common complexometric indicators include Mordant Black II, Catechol Violet, and Xylene Orange, all of which change color upon binding with metal ions such as Ca\(^{2+}\) or Mg\(^{2+}\).
- Ferroin, however, is primarily a redox indicator used in redox titrations, especially with iron(II) and iron(III) ions, and does not act as a complexometric indicator.
- Therefore, Ferroin is an exception and is not used as an indicator in complexometric titrations.