Question

Do iron (III) chloride, potassium iodide, or potassium chloride catalyze the decomposition of hydrogen peroxide?

Answer 1

Iron (III) chloride catalyzes the decomposition of hydrogen peroxide because the decomposition of hydrogen peroxide is usually inhibited by the presence of ions such as phosphate ions in solution. The iron ions that would result from the dissolution of iron (III) chloride have a charge of 3+ and would bond with the -3 charged phosphate ions, creating a non-charged FePO4 molecule and removing the decomposition inhibitor from the solution. Potassium iodide and potassium chloride both are more strongly bonded than a transition metal compound and would lack the necessary charged iron ion when added to hydrogen peroxide.