Final answer:
The reactivity of 4-methoxyacetophenone and its conjugate species formed upon reaction with sodium hypochlorite is determined by their electron-donating or accepting properties.
Step-by-step explanation:
The difference in reactivity between 4-methoxyacetophenone and its corresponding conjugate species formed upon reaction with sodium hypochlorite is due to the electron-donating nature of the methoxy group.
The methoxy group increases the electron density on the aromatic ring, making it more likely to donate electrons. In contrast, the conjugate species formed after reaction with sodium hypochlorite is more likely to accept electrons due to the presence of oxygen and chlorine atoms.