1. The hydrolysis of the acid anhydride X1 by OHis catalyzed by Zn2+ ions. The rate of equation is of the form: r=k[X1][Zn2+][OH] It is also known that the addition of Zn2+ does not accelerate hydrolysis by H2O or attack by other nucleophiles. Suggest a mechanism for this reaction. 2. Compound X2 reacts with Zn(ClO4)26H2O to give complex [Zn(X2)(OH)]+that is a model for the active site of carbonic anhydrase. Suggest a structure for this complex. What properties does X2 possess that a) mimic the coordination site in carbonic anhydrase? b) control the coordination geometry around the Zn2+ ion in the model complex? 3. [CrL3]3, where H2L=1,2(OH)2C6H4, is a model complex for enterobactin. How is this model related to enterobactin, and what is the reason for chromium-for-iron substitution