(b) Determine the correct order of C-O stretching frequency in the IR spectrum for the following compounds? Explain your answer. [Fe(CO)5], [Fe(CO).Brz], [Fe(CO)_]2- [7 marks] (c) Draw the structures of intermediate and product the following reaction [Fe(n-C5H5)(CH3)(CO)2] + PPh3 [4 marks] (d) Draw the structure of the intermediate and product for the reaction of (C6H3)3P CO (X= F, CI, Br, and I) with O2 (C6H5)3P How does the rate of reaction vary with X? Explain your