A 100-mL sample of water is titrated with EDTA solutions in problem 2. The same amount of Mg2+ is added as previously, and the volume of EDTA required is 31.84mL.

What volume of EDTA is used in titrating the Ca2+ in hard water?

Previous answers are:
Moles of Ca2+ : 0.005113
Molarity of Ca2+ in 250mL solution: 0.02045M
Moles of Ca2+ are in 25.00-mL aliquot of solution in 1b : 0.0005113 moles

A blank containing a small measured amount of Mg2+requires 3.21 mL of EDTA to reach the end point. An aliquot to which the same amount of mh2+ is added requires 24.95 mL of the EDTA to reach end point.
Milliliters of EDTA are needed to titrate the Ca2+ ion in aliquot - 21.74 mL
Moles of EDTA in the volume 0.00015113
Molarity of the EDTA solution : 0.02351 M

To find the volume of EDTA used to titrate the Ca2+ in hard water, we need to calculate the moles of Ca2+ and then use the mole ratio to determine the volume of EDTA.

1. Moles of Ca2+ in the 100 mL water sample = Moles of Ca2+ in the 25.00 mL aliquot / 0.025 L (conversion from mL to L)
Moles of Ca2+ in the 100 mL water sample = 0.0005113 moles / 0.025 L
Moles of Ca2+ in the 100 mL water sample = 0.020452 moles

2. From the mole ratio between Ca2+ and EDTA (1:1), we can determine the moles of EDTA required to titrate the Ca2+.
Moles of EDTA = Moles of Ca2+
Moles of EDTA = 0.020452 moles

3. Finally, we can calculate the volume of EDTA required to titrate the Ca2+.
Volume of EDTA = Moles of EDTA / Molarity of EDTA solution
Volume of EDTA = 0.020452 moles / 0.02351 M
Volume of EDTA = 0.871 mL

Therefore, the volume of EDTA used to titrate the Ca2+ in hard water is 0.871 mL.

To find out the volume of EDTA used in titrating the Ca2+ in hard water, we can use the following steps:

Step 1: Calculate the moles of Ca2+ in the volume aliquot.
Given that the moles of Ca2+ in the 25.00-mL aliquot of solution is 0.0005113 moles, we can use the following formula:
moles of Ca2+ = volume (in liters) x molarity of Ca2+
0.0005113 moles = 0.025 L x 0.02045 mol/L

Step 2: Calculate the moles of EDTA used in titrating Ca2+ in the aliquot.
To find the moles of EDTA used, we can use the mole ratio between Ca2+ and EDTA. From the previous question, we know that the mole ratio is 1:1. Therefore, the moles of EDTA used is also 0.0005113 moles.

Step 3: Calculate the volume of EDTA used in titrating Ca2+.
We can use the following formula to find the volume of EDTA used:
volume (in liters) = moles of EDTA / molarity of EDTA
volume (in liters) = 0.0005113 moles / 0.02351 mol/L

Now, we can convert the volume to milliliters:
volume (in mL) = volume (in liters) x 1000
volume (in mL) = (0.0005113 moles / 0.02351 mol/L) x 1000

Calculating the above expression gives us the volume of EDTA used in titrating the Ca2+ in hard water as approximately 21.74 mL.

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