EDTA is a common chemical species that can be used to determine water hardness, (i.e, the sum of um and magnesium ions in a water sample). EDTA (designated as HY') is also known to react in a 1:1 stoichiometry with most metal ions of +2 charge or greater. reaction with calcium ion would be: Ca2+ (aq) + H,Y2. (aq) â CaH2Y (aq) conducting titrations, a common term that is employed is called concentration, which is often defined as the number of moles of a substance (often called the solute) L of a solution. This definition is called Molarity and is given the symbol M. 1. (1.5 point) Calculate the Molarity (M) of an EDTA solution if 3.722 g of Na,EDTA 2H,O are dissolved in 1.0 L of water. (Na EDTA2H,O, MM 372.24 g/mole). Show your work! 2. (2 points total) A 5.00 mL tap water sample was measured out with a volumetric pipette, and added to a 25 mL Erlenmyer flask. It was then titrated with a 0.0100 M Na EDTA 2H2O solution, and found to take 0.635 mL of the EDTA solution to reach the blue endpoint. a) How many moles of the 0.0100 M Na,EDTA 2H,0 were added in the titration reaction? S calculation. b) How many moles of calcium ions were reacted? Show calculation. 63