Carbonyls (as in 4 and 5) are always electron withdrawing due to the Oxygen's electronegativity. Similarly, the oxygens on the nitrate (1) are electron withdrawing.

Carbonyls (as in 4 and 5) are always electron withdrawing due to the Oxygen's electronegativity. Similarly, the oxygens on the nitrate (1) are electron withdrawing.

A tert-butyl functional group is electron donating and will therefore activate the ortho and para positions. However, the ortho positions are sterically hindered by the bulky tert-butyl group. Therefore, the para position will be favored.

A tert-butyl functional group is electron donating and will therefore activate the ortho and para positions. However, the ortho positions are sterically hindered by the bulky tert-butyl group. Therefore, the para position will be favored.

is the only electron-withdrawing substituent because it contains two electronegative oxygen atoms which pull electrons from the benzene ring towards itself. This effect is electron-withdrawing and makes the ring slightly positive in charge. All the other substituents are electron-donating groups, which activate the ring for electrophilic addition.

is the only electron-withdrawing substituent because it contains two electronegative oxygen atoms which pull electrons from the benzene ring towards itself. This effect is electron-withdrawing and makes the ring slightly positive in charge. All the other substituents are electron-donating groups, which activate the ring for electrophilic addition.

is the only electron-donating group listed. Therefore, it will add to the ortho and para positions on phenol. The rest of the substituents are highly electron-withdrawing groups and will add to the meta positions on phenol.

Several resonance structures can be drawn for the molecule nitrobenzene. These are shown below.

From these resonance structures, an overall molecular electronic distribution can be determined:

Because the overall charge distribution puts partial positive charges on carbons , , and , these carbons have an increased electrophilic character. Therefore, these carbons are less likely than the other carbons to accept an incoming electrophilic substituent, making these positions less likely to be substituted. By default, carbons , and , known as the meta positions are the only ones nucleophilic enough to carry out this reaction.

Several resonance structures can be drawn for the molecule nitrobenzene. These are shown below.

From these resonance structures, an overall molecular electronic distribution can be determined:

Because the overall charge distribution puts partial positive charges on carbons , , and , these carbons have an increased electrophilic character. Therefore, these carbons are less likely than the other carbons to accept an incoming electrophilic substituent, making these positions less likely to be substituted. By default, carbons , and , known as the meta positions are the only ones nucleophilic enough to carry out this reaction.

is the only electron-donating group listed. Therefore, it will add to the ortho and para positions on phenol. The rest of the substituents are highly electron-withdrawing groups and will add to the meta positions on phenol.