Step 1: Understand what +M effect means. +M effect refers to the ability of a group to donate electron density to a molecule through resonance.
Step 2: Identify the –OH group. The –OH group is known as a hydroxyl group.
Step 3: Learn how the –OH group donates electron density. The lone pair of electrons on the oxygen atom in the –OH group can be shared with the rest of the molecule through resonance.
Step 4: Conclude that since the –OH group donates electron density, it exhibits a +M effect.
