Electrophilic Substitution Part II - Orientation & Reactivity of mono and disubstituted benzene 

This video help to identify activating ( strongly, moderately, Weakley) and deactivating ( strongly, moderately, and weakley) functional group in electrophilc substitution reaction of benzene. It also help the product,whether ortho, para ,meta isomer during the reaction .It help to predict the product in the reaction. It also help to find out the position at which the new group enters when third electrophile attacks