Practicing Success
Statement I: It is difficult to replace chlorine by –OH in chlorobenzene in comparison to that in chloroethane Statement II: Chlorine – carbon (C–Cl) bond in chlorobenzene have double bond character due to resonance. |
Both statement I and statement II are correct and statement II is the correct explanation of statement I Both statement I and statement II are correct but statement II is not the correct explanation of statement I Statement I is correct but statement II is false Statement I is false but statement II is correct |
Both statement I and statement II are correct and statement II is the correct explanation of statement I |
The answer is (1) both statement I and statement II are correct and statement II is the correct explanation of statement I. Statement I is correct because the chlorine-carbon bond in chlorobenzene has a partial double bond character due to resonance. This makes the chlorine atom less electronegative and less likely to be replaced by a nucleophile. Statement II is also correct because the partial double bond character in the chlorine-carbon bond is caused by resonance. This means that statement II provides the reason for the decreased reactivity. Here is a diagram that shows the resonance structures of chlorobenzene: As you can see, the chlorine atom is sharing a pair of electrons with the benzene ring, giving the bond a partial double bond character. This makes the chlorine atom less electronegative and less likely to be replaced by a nucleophile. Therefore, both statement I and statement II are correct and statement II is the correct explanation of statement I. |