When all the metal ions are stripped off of the indicator, a color change from pink to blue
occurs. This signals the end of titration, and that an equivalence point between the metal ions
and the EDTA has been reached. By finding the volume of EDTA solution titrated and knowing
the molarity of the solution, the moles of EDTA could be found. This is equal to the moles of
Calcium. Knowing this can then allow the hardness of water to be found, which sample1 was 90ppm and sample 50ppm