Question

write the reaction between EDTA and magnesium ion in hard water

Answer 1

Ca+2(aq)     +   EDTA-2(aq)       à    CaEDTA(aq)  

Answer 2

Explanation:

Calcium and magnesium salt dissolved in water cause water hardness.The hardnes of the water can be estimated with the help of the EDTA titration.

EDTA =  Ethylenediaminetetra acetic acid

The reaction between magnesium ion and EDTA is given as:

$Mg^{2+}(aq)+EDTA^{4-}(aq)\rightarrow (Mg-EDTA)^{2-}(aq)(complex)$