Identify the wrong statement among the following related to phenol. (a) Phenol is a weaker acid than carbonic acid. (b) When distilled with zinc, phenol gives benzene. (c) Among the three isomers of nitrophenol, the one that is least soluble in water is \(\mathrm{p}\) -nitrophenol. (d) Formation of phenol from chlorobenzene is an example of nucleophilic aromatic substitution.

Understanding the acidic strength of various compounds is a vital concept in chemistry. Phenol, known for its aromatic ring with a hydroxyl group, has a distinctly different acidic strength compared to other acids, such as carbonic acid. Phenol is actually more acidic than carbonic acid because the negative charge created when a hydrogen ion (proton) is lost from the hydroxyl group of phenol can be delocalized over the aromatic ring. This delocalization provides stability to the phenoxide ion and makes the loss of the proton more favorable.

It's important to note that acidity in organic compounds like phenol can be influenced by factors such as resonance and the electronegativity of attached groups, which can stabilize or destabilize the negative charge on the anion.

Phenol is quite reactive due to its aromatic structure and the presence of a hydroxyl group. One of the most notable reactions is its reduction when treated with zinc. This reaction strips away the oxygen group, effectively transforming phenol into benzene.

Other reactions consist of electrophilic aromatic substitution, where phenol can react with various electrophiles due to the increased electron density of the benzene ring imparted by the hydroxyl group. For instance, nitration of phenol can occur more readily than with benzene itself, leading to the formation of nitrophenol compounds. These reactions highlight the importance of understanding the unique chemical behavior phenol exhibits due to its structure.

The solubility of different isomers of nitrophenol in water is a subtle yet intriguing topic. The solubility largely depends on the isomer's ability to form hydrogen bonds with water. Due to intramolecular hydrogen bonding, ortho-nitrophenol has reduced solubility as these bonds limit its ability to interact with water molecules.

Comparatively, para-nitrophenol has better solubility since the positions of the nitro group and the hydroxyl group on the aromatic ring allow it to form intermolecular hydrogen bonds with water. Meta-nitrophenol also has better solubility than the ortho isomer but not as high as the para isomer due to the relative positions of its functional groups. Understanding these differences in solubility is crucial for various applications, including the manufacturing of pharmaceuticals and dyes where specific isomers must be separated.

Nucleophilic aromatic substitution is a type of reaction where an electron-rich nucleophile replaces a leaving group on an aromatic ring. A classic example is the production of phenol from chlorobenzene. In this reaction, the nucleophile (often a hydroxide ion) attacks the chlorobenzene, displacing the chloride ion and forming a new bond.

This reaction is facilitated by the presence of electron-withdrawing groups that make the carbon more susceptible to nucleophilic attack. In the case of chlorobenzene, it’s the chlorine atom that makes the ortho and para positions more electrophilic, allowing the nucleophile to bind and displace the chlorine atom. Such reactions are a cornerstone of organic synthesis, leading to a variety of compounds with practical importance in industries ranging from pharmaceuticals to agrochemicals.