4. Oxidation of Fe(s) with dissolved oxygen (4 pts). Given [Fe2+]=106M,T=298K, and consider two half-reactions: Fe(s)Fe2++2e,O2(aq)+4H++4e2H2O,reduction,Eredo=1.27Voxidation,Eoxo=0.44V Assuming the activity of solids and liquids is equal to 1. Neglecting activity coefficient corrections. Note that in their current states, the two half-reactions are not balanced yet. Calculate the equilibrium constant and Gmxno for the corrosion of Fe(s) to Fe2+ by dissolved oxygen. Determine the oxygen concentrations that are needed for pH values equal to 6.5 and 7.2, such that the reaction is thermodynamically favorable. 5. Advanced Oxidation Processes (4 pts). N-Nitrosodimethylamine (NDMA) with a chemical formula of C2H6N2O is a compound of concern present in many secondary and tertiary treated wastewater effluents. The second order rate constant (kR) of the reaction of HO and NDMA is 4108L/mole.s. Calculate the time required to lower the concentration of NDMA from 200mg/L to 20mg/L for a HO concentration of 109mole/L using a completely mixed batch reaction (CMBR)