One of these compounds will react more slowly with electrophiles in electrophilic aromatic substitution than benzene does, and one of them will react more quickly. Explain why with words, structures, and a single energy-reaction coordinate diagram.
The compounds in the image are methyl benzoate and phenyl acetate. Electrophilic aromatic substitution is a chemical reaction whereby an atom in an aromatic ring is swapped out for an electrophile.
The rate of substitution is affected by the substituents already attached to a benzene ring, specifically whether the group donates electrons (which increases the reaction rate) or withdraws an electron.
Because of the electron donating properties of oxygen when directly attached to the benzene ring, the molecule with oxygen directly attached to the benzene ring will react at a much faster rate than benzene. Of the two molecules in the image, that would be the phenyl acetate.
Because of the electron removing properties of the carbonyl group attached to the benzene ring, the molecule with carboxyl group directly attached to the benzene ring will react at a much slower rate than benzene. Of the two molecules in the image, that would be the methyl benzoate.