Assertion (A) o-nitrophenol is less soluble in water than the $m$ and p-isomers.
Reason (R) $m$ and $p$-nitrophenols exist as associated molecules.
Assertion (A) Ethanol is a weaker acid than phenol.
Reason (R) Sodium ethoxide may be prepared by the reaction of ethanol with aqueous NaOH .
Assertion (A) Phenol forms 2, 4, 6-tribromophenol on treatment with $\mathrm{Br}_2$ in carbon disulphide at 273 K .
Reason (R) Bromine polarises in carbon disulphide.
Assertion (A) Phenols give o -and p -nitrophenol on nitration with conc. $\mathrm{HNO}_3$ and $\mathrm{H}_2 \mathrm{SO}_4$ mixture.
Reason $(\mathrm{R})-\mathrm{OH}$ group in phenol is $\mathrm{o}-\mathrm{p}$-directing.
Write the mechanism of the reaction of HI with methoxybenzene.
In case of alkyl aryl ethers, the products are always phenol and an alkyl halide because due to resonance $\mathrm{C}_6 \mathrm{H}_5-\mathrm{O}$ bond has partial double bond character. The mechanism is given below
Mechanism Protonation of anisole gives methylphenyl oxonium ion.
In this ion, the bond between $\mathrm{O}-\mathrm{CH}_3$ is weaker than the bond between $\mathrm{O}-\mathrm{C}_6 \mathrm{H}_5$ which has partial double bond character. This partial double bond character is due to the resonance between the lone pair of electrons on the O -atom and the $s p^2$ hybridised carbon atom of the phenyl group. Therefore, attack by $I^{-}$ion exclusively breaks the weaker $\mathrm{O}-\mathrm{CH}_3$ bond forming methyl iodide and phenol.
