Packaging Detail : Packaging Details: Packing 5, 10, 25 , 210 10) Hardness Indicator Powder Calmagite :In the titration of calcium and magnesium with EDTA the indicator calmagite works in the following way. When a small amount isadded to a solution containing magnesium at pH 10, red MgIn??? forms. As EDTA titrant is added, free magnesium ions in solution react with it. After all the free magnesium is complexed, the next portion of EDTA removes magnesium from the indicator complex, converting the indicator to the blue HIn2??? form. The pH must be near 10 because at pH values above 12 or below 8 the free indicator is red like the magnesium complex, and therefore no color change can be observed.The calcium-calmagite complex is too weak to function as an indicator (log K (CaIn) = 3.7 at pH10). Calcium can, however, be titrated and an end point obtained when a trace of magnesium is present. In this experiment a small amount of magnesium is added to the titrant since the prim
