9. Which substance is used to determine the hardness of water using a simple titration? a) Mg(EDTA) b) Fe(EDTA) c) Na2(EDTA) d) Co(EDTA)
Hardness of water is determined by titrating with a standard solution of ethylene diamine tetra acetic acid (EDTA) which is a complexing agent. Since EDTA is insoluble in water, the disodium salt of EDTA is taken for this experiment. EDTA can form four or six coordination bonds with a metal ion.
