Standard CaCO, is used to standardize the EDTA solution prior to titration. Suppose 0.385 g of CaCO, was dissolved and diluted to 250.0 mL. A 25.0 mL aliquot of this standard CaCO3 solution was then titrated to endpoint using 29.50 ml. of the EDTA solution. Afterwards, the standardized EDTA solution was used to analyze the hardness of a 1000-ml water sample buffered at pH 10. The sample required 44.35 ml. of the EDTA solution to reach the endpoint. Determine the hardness of the sample in ppm CaCO3.

A 340.00 mL solution of 0.00175 M AB2 is added to a 140.00 mL solution of 0.00235 M CD4. What is pQsp for AD2?

A 1.00 mL aliquot of a solution containing Cu and Ni is treated with 25.00 ml. of a 0.03468 M EDTA solution. The solution is then back titrated with 0.02308 M Zn+ solution at a pH of 5. A volume of 20.28 ml. of the Zn solution was needed to reach the xylenol orange end point. A 2.000 mL aliquot of the Cu* and Ni* solution is fed through an ion- exchange column that retains Ni?*. The Cu?+ that passed through the column is treated with 25.00 mL of 0.03468 M EDTA. This solution required 23.18 mL of 0.02308 M Zn* for back titration. The Ni extracted from the column was treated witn 25.00 mL of 0.03468 M EDTA. How many milliliters of 0.02308 M Zn+ is required for the back titration of the Ni solution? volume: ml.