Final answer:
The decomposition of hydrogen peroxide normally occurs through the action of a catalyst, such as iodide ion, which lowers the activation energy and facilitates the chemical change.
Step-by-step explanation:
A possible mechanism for the decomposition of hydrogen peroxide is the presence of a catalyst such as the iodide ion (I). The decomposition of hydrogen peroxide into water (H₂O) and oxygen gas (O₂) can be represented by the reaction 2H₂O₂ (aq) → 2H₂O(l) + O₂(g). Catalysts work by providing an alternative reaction pathway with a lower activation energy, which increases the rate at which the hydrogen peroxide decomposes. This process is a chemical change where the chemical bonds within hydrogen peroxide molecules are broken, and new bonds are formed to create water and oxygen.
Options A) Photodissociation and C) Electrolysis are not typical mechanisms for the decomposition of hydrogen peroxide in practical settings. Electrolysis is more commonly associated with the decomposition of water into hydrogen and oxygen gas, where an ionic solute is added to increase water's electrical conductivity and voltage is applied to initiate the reaction.