Answer:
a. benzaldehyde (2), p-methylbenzaldehyde (1), p-chlorobenzaldehyde (3)
b. chlorobenzene (2), o-dichlorobenzene (3), benzene (1)
Explanation:
a. Based on inductive effect, p-chlorobenzaldehyde (3) is the least reactive, benzaldehyde (2) is less reactive while p-methylbenzaldehyde (1) is the most reactive.
b. Based on the location of either meta, ortho and para on the benzene ring, benzene is the most reactive (1), chlorobenzene is less reactive (2), o-dichlorobenzene (3) is the least reactive.
