Question

Expand EDTA and write its structure. How is this reagent used in titrimetric

analysis? Explain.

Answer 1

EDTA (ethylenediaminetetraacetic acid) is an organic compound, a chelating agent with the molecular formula (HOOCCH₂)₂N(CH₂)₂N(CH₂COOH)₂ containing four carboxyl groups and two amine groups. EDTA can sequester metal ions, including Ca²⁺, Mg²⁺, and Fe³⁺.

Interaction between EDTA and metal ions results in the release of hydrogen ions decreasing pH. This process leads to changes in the color of an indicator. As a result, EDTA is used in a titrimetric analysis to evaluate metal ions concentration in a solution.