You run an analysis of a water sample according to Part 1 of the laboratory procedure, titrating the solution with 0.0100 M sodium hydrogen EDTA. A sample of 25.00 mL of water is pipetted into a clean Erlenmeyer flask, and four drops of calmagite indicator are added, resulting in a pink solution. The initial buret reading is 0.52 mL. EDTA is added until the solution turns blue. The final volume in the buret is 15.54 mL.

1. Determine the volume of titrant required to reach the equivalence point.

2. Determine the number of moles of EDTA used

3. Determine the total number of moles of Ca²⁺ + Mg²⁺ titrated.

4. Determine the concentration of Ca²⁺ + Mg²⁺ ions in the water sample in M