Question

25.00 mL aliquots of the solution from Part 1 are titrated with EDTA to the Eriochrome Black T end point. A blank containing a small measured amount of Mg2+ requires 2.60 mL of the EDTA to reach the end point. An aliquot to which the same amount of Mg2+ is added requires 28.55 mL of the EDTA to reach the end point.

How many milliliters of EDTA are needed to titrate the Ca+2 ion in the aliquot?

How many moles of EDTA are there in the volume obtained in the previous question?

What is the molarity of the EDTA solution?

Answer 1

<b>Without all of the question it is impossible to answer any but the first part.</b>
25.00 mL aliquots of the solution from Part 1 are titrated with EDTA to the Eriochrome Black T end point. A blank containing a small measured amount of Mg2+ requires 2.60 mL of the EDTA to reach the end point. An aliquot to which the same amount of Mg2+ is added requires 28.55 mL of the EDTA to reach the end point.

How many milliliters of EDTA are needed to titrate the Ca+2 ion in the aliquot?
<b>28.55-2.60 = ??</b>

How many moles of EDTA are there in the volume obtained in the previous question?
<b>moles EDTA in 100 mL x 10 = moles EDTA in 1 L.

What is the molarity of the EDTA solution? </b>