5. Balance the given equation using the half-reaction method. Identify the ion or element that gained electron and indicate the number of electrons gained. Identify the ion or element that lost electron and indicate the number of electrons lost. Fe2+ + Cl2 Fe3+ + Cr 6. What is the molar mass of the following compounds. a. Epsom Salt, the chemical formula is MgSO4.7H20 b. Ammonium phosphate