An EDTA solution was prepared by dissolving approximately 4 g of the disodium salt in approximately 1 L of water. An average of 37.99 mL of this solution was required to titrate 50.00-mL aliquots of a standard that contained 0.6891 g of MgCO₃ per liter. Titration of a 25.00-mL sample of mineral water at pH 10 required 18.81 mL of the EDTA solution. A 50.00-mL aliquot of the mineral water was rendered strongly alkaline to precipitate the magnesium at Mg(OH)₂. Titration with a calcium-specific indicator required 31.54 mL of the EDTA solution. Calculate
(a) The molar concentration of the EDTA solution.
(b) The concentration of CaCO₃ in the mineral water in ppm.
(c) The concentration of MgCO₃ in the mineral water in ppm.