0.506g of EDTA was dissolved in 100mL of deionised water, transferred to a 1L volumetric flask and made up to the mark with deionised water. When this solution was placed in a burette and titrated against 10mL aliquots of tap water, the average titre result was found to be 6.50 ml of EDTA. Show all your steps in order to calculate the concentration of water hardness for this tap water in ppm. Comment on the type of water for this tap water, based on your calculations.