A student proposes the following three elementary steps as a mechanism for the aqueous oxidation of iodide ion by hydrogen peroxide under acidic conditions.
Step 1: I−+H2O2→IO−+H2O
Step 2: IO−+H+→HOI
Step 3: HOI+I−+H+→I2+H2O
The overall reaction is believed to be H2O2+2I−+2H+→I2+2H2O.
Answer the following questions.
(a) Combine the three elementary steps algebraically to obtain the overall balanced chemical equation predicted by the mechanism. Show clearly how species cancel or add.
(b) Identify every intermediate and every reactant or product in the proposed mechanism. Justify your classifications.
(c) Describe how the principle of conservation of mass and the principle of conservation of charge are satisfied when the three steps are summed. Cite specific coefficients, atoms, and charges in your explanation.
(d) Explain one experimental observation that could be used to confirm that HOI is an intermediate rather than a final product.