A seven step mechanism can be used to describe the atmospheric reactions involving formaldehyde and nitrogen oxides at 1 atm and T=298C as presented by Seinfeld, These photochemical reactions lead to the formation of ozone:2 Step 1: NO2+hvNO+O k1=0.533min1 Step 2: O+O2+MO3+M k2=2.21105ppm2min1 Step 3: O3+NONO2+O2k3=26.7ppm1min1 Step 42:HCHO+hv2HO2+CO k+a=1.6103min1 Step 4b:HCHO+hvH2+COk4b=2.11103min1 Step 5: HCHO+OHHO2+CO+H2Ok3=1.62104ppm1min1 Siep 6: HO2+NONO2+OH.K6=1.22104ppm1min1 Step 7: OH+NO2NO3k7=1.62104pmm1min1 The photolysis resctions of step 1,4a and 4b are written for the case where the incoming solar radiation is assumed to be constant at the middiyy value of kim thus leading to the given rate constants. A more detailed model would be to have the rate constants for these steps vary with the time of the day according to ki=kiMsin[242(t6)]forsin[242(t6)]>0 [Equation 1] ki=0 for all other vatues of t Where t is the time in hours on a 24 hourvday basis and the solar rodiation begins at 6 am and ends at 6pm. All of the reactions in the mechanism are considered to be elementary as written. For example, the rate of the second step is given by: 2=k2CoCo2CM Where the concentrations are in ppm. CM is the concentration of third bodies, which is considered to be at a constant value of 106ppm and CO2 the concentration of oxygen is constant at 0.21106ppm. The simplest applications of chemical engineering top urban smog simulation involves considering the atmosphere below an inversion layer to be a batch reactor with no input or output terms. The resulting material balance for each of the species in the mechanism can be made and expressed as ordinary differential equations. Thus for ozone: dtdCO3=k2COCO2CMk3CO3CNO Similar material balances can be made for the other reacting components, including the free radicals. Typical initial conditions for all free radicals are that the concentrations are essentially zero. Consider a simplified model for photochemical smog that is represented by seven step mechanism for formaldehyde. A. Find the concentration profiles for O3,NO2,NO, and HCHO for the given initial conditions and the constant values of photolysis reaction rate constants of step 1,4a, and 4b. B. Repeat part a for a single 24 hour day starting at midnight with the same initial conditions but with the three photolysis reactions varying according to the general relationship of equation 1