4. At a wastewater treatment plant, FeCl3(s) is added to remove excess phosphate from the effluent. a. What is the chemical formula of the iron ion (Fe') with which FeCl3(s) is formed? What does (s) mean? b. When added to water the ionic compound FeCl3(s) decomposes into ions and the iron cation (Fe?) reacts with phosphate, PO43- to form FePO4(s). Write and balance the two chemical reactions describe above. 5. At temperature 0=25C and under a pressure p=1.01x105 Pa (constant conditions), a volume V1=10ml of a solution of FeCl3 of molar concentration C1=8x102mol.1-1 is added to a volume V2=10ml of wastewater of a molar concentration Cz=5x10-mol.1-2 of phosphate (PO43-). After mixing, a yellow precipitate is observed a. What is the initial state of the system? b. Can you determine using a table like shown in class what is the maximal advancement (xt) and the limiting reactant?