We need to calculate the concentration of a pollutant A following a spill into a river which flows by our chemical plant at 10^5 gal/h at 5 mph. There is a waterfall just upstream, so the water is saturated with air at CO2 = 1.5 × 10^-3 moles/liter. The river bottom is rocky so that the flow is well mixed radially. This chemical is oxidized by dissolved O2 with a rate r = kCACO2 with k= 2000 liters/mole h and r in moles/liter h. (a) Consider a steady leak of 10 gal/h at CA = 0.1 moles/liter. What is CAo in the river after mixing? (b) If trout are killed if CA > 10^-6 moles/liter, estimate the downstream distance at which the trout be killed. [You don’t need to solve a second-order equation.] (c) Suppose that the leak is 100 gal/h of 10 molar A. What is CAo in the river after mixing? (d) If carp are not harmed by A but they die if CO2 < 10^-4 moles/liter, estimate the downstream distance at which the carp be killed for the spill in part (c), assuming no replenishment of the O2. [Again, you do not need to solve a second-order equation.]