Final answer:
To find the theoretical volume of 0.01 M EDTA needed to titrate a 20 ml CaCO3 solution standardized at 1000 ppm, convert the ppm to molarity, use the 1:1 molar ratio between CaCO3 and EDTA, and calculate the volume. The result is 20 ml of EDTA is required.
Step-by-step explanation:
Theoretical Volume Calculation for Standardization Titrations
To calculate the theoretical volume required for the standardization titrations of a 20 ml CaCO3 solution with 0.01 M EDTA, we use the stoichiometry of the reaction between CaCO3 and EDTA. First, we convert the concentration of CaCO3 in ppm to molarity. Given 1000 ppm CaCO3 is equivalent to 1000 mg/L, and the molar mass of CaCO3 is approximately 100.09 g/mol, we find the molarity of CaCO3 in the solution:
Molarity of CaCO3 = (1000 mg/L) / (100.09 g/mol × 1000 mg/g) = 0.01 M
Since the reaction between CaCO3 and EDTA occurs in a 1:1 molar ratio, 20 ml of 0.01 M CaCO3 will require an equivalent amount of 0.01 M EDTA:
Theoretical volume of 0.01 M EDTA = Volume of CaCO3 solution × Molarity of CaCO3 / Molarity of EDTA
= 20 ml × 0.01 M / 0.01 M = 20 ml
This means 20 ml of 0.01 M EDTA would be theoretically required to titrate 20 ml of the CaCO3 standard solution.