A freshwater sample containing Ca2+ and Mg2+ will be analyzed using EDTA titration. The EDTA titrant was standardized by dissolving 0.5005g of CaCO3 (99.00% purity) in 100.0mL. A 10.00-mL aliquot was then titrated using 24.93 mL of EDTA titrant to the Eriochrome Black T endpoint. A sample with a volume of 250.00 mL is titrated with 20.32 mL of the EDTA titrant in an ammonia buffer at pH 10.00. Another 250.00 mL sample was then treated with NaOH to precipitate Mg(OH)2 and was then titrated at pH 13.00 with 10.43 mL using the same EDTA solution. FW: CaCO3 (100.09 g/mol) & MgCO3 (84.314 g/mol) c. What is the total hardness of the water sample expressed as ppm CaCO3.

A freshwater sample containing Ca2+ and Mg2+ will be analyzed using EDTA titration. The EDTA titrant was standardized by dissolving 0.5005g of CaCO3 (99.00% purity) in 100.0mL. A 10.00-mL aliquot was then titrated using 24.93 mL of EDTA titrant to the Eriochrome Black T endpoint.

A sample with a volume of 250.00 mL is titrated with 20.32 mL of the EDTA titrant in an ammonia buffer at pH 10.00. Another 250.00 mL sample was then treated with NaOH to precipitate Mg(OH)2 and was then titrated at pH 13.00 with 10.43 mL using the same EDTA solution.

FW: CaCO3 (100.09 g/mol) & MgCO3 (84.314 g/mol)

c. What is the total hardness of the water sample expressed as ppm CaCO3.