Phenol and resorcinol are both resistant to mild oxidation.
Hydroquinone can under go mild oxidation by ammoniacal silver nitrate or "Tollen's Reagent".
Tollen's Reagent is a solution of diammine siver(I) ions:
They can be regarded as
Phenol is :
Resorcinol is 1, 3 dihydroxybenzene:
Hydroquinone is 1, 4 dihydroxybenzene:
This will undergo mild oxidation to benzoquinone:
In doing so silver(I) ions are reduced to metallic silver giving the characteristic "silver mirror".
Espero que esto sea lo que pedían .