Consider the following mechanism: 1) A + h? ® A* rate1 = Ia excitation of A (a constant) 2) A* + A ® A2 rate2 = k2[A][A*] formation of product 3) A* ® A + h?f rate3 = k3[A*] fluorescence of A* a) Write an expression for d[A2]/dt. b) Apply the steady state approximation to A* and derive an expression for the steady state concentration of A*. c) Use the results of a and b to write an expression for d[A2]/dt in terms of only [A] and various constants. d) If we define the quantum yield as ? = d[A2]/dt / Ia , develop an expression for the quantum yield of the reaction. e) If the fluorescence is minimal (k3 = 0), what would be the value of?