[craken66]

Generally, hydroxide group is known as electron-donating group when directly attached to benzene ring.

Actually, oxygen of hydroxide is heavily electronegative, and likes electrons.

then, Why is hydroxide group an electron-donating group?

I think that hydroxide is more like electron-withdrawing group when directly bound to aromatic nucleus.

What do you think?

Thank you for your reading!!

[KritikalMass]

Look at resonance. Does the hydroxyl group have any spare electrons that it can donate to the benzene ring?