Question 3 3 pts The indicator used in this experiment is Calmagite, and to ensure we can monitor the color change clearly, the pH of the calcium solution needs to be adjusted to Select | using a pH buffer solution. In this experiment, when Calmagite binds to the metal ions in the water sample, the solution before EDTA titration will exhibit a color of Select and the solution after the EDTA titration will exhibit a color of Select