Concerning EDTA titrations, which of the following is correct?
EDTA forms 1:2 complexes with metal ions.
The most widely used indicators are murexide and Eriochrome Black T.
In the presence of NaOH, EDTA reacts only with Mg+2 ions, using murexide indicator.
The water hardness is usually expressed as MgCO3 mg/L water.
EDTA solution was standardized using NaCl.