# What is "EDTA"?

$\text{EDTA}$ is a so-called sequestrating agent.........
$\text{EDTA}$ as a multidentate ligand, that usually reacts with a metal cation in water with 1:1 stoichiometry.
M^(n+) + "EDTA" rarr M("EDTA")^(+n-4)+4H^+
To perform a complexometric titration, typically the solution is buffered to give a set $p H$. Some indicating agent, usually the delightfully named $\text{eriochrome black T}$ is also employed to signal the endpoint of the reaction.