A 20.00-mL sample of hard water (with Mg2 added) is titrated with 0.0105 M EDTA. A blank solution with the same amount of Mg2 requires 2.35 mL of EDTA to reach its end point. A total of 34.13 mL of EDTA was used for the titration of the 20.00-mL sample of hard water (with Mg2+ added). M. W. CaCO3= 100.1 g/mol. Requried:
a. How many moles of EDTA are rquired to titrate the Ca²+ present in the 20.00-mL sample?
b. Assuming that Cat is present as Cacos, how many grams of CaCO3 are there in 20.00 mL of hard water?
c. What is the concentration of CaCO3 in parts per million?