Statement 1 On heating with con. \(\mathrm{H}_{2} \mathrm{SO}_{4}\), benzene gives benzene sulphonic acid which when heated with superheated steam under pressure gives back benzene.

Benzene sulfonation is a process where a benzene ring, a common structure in organic chemistry, undergoes an electrophilic aromatic substitution. During this reaction, one hydrogen atom in the benzene molecule is replaced by a sulfonyl group (-SO₃H).

This transformation is caused by the electrophile, which in this scenario is sulfur trioxide (SO₃) generated from concentrated sulfuric acid (H₂SO₄). The overall reaction involves the addition of the electrophile to the aromatic ring, followed by the loss of a hydrogen ion (proton), resulting in the formation of benzene sulfonic acid (C₆H₅SO₃H).

Here's the equation translated from the step-by-step solution:
\[\mathrm{C}_{6}\mathrm{H}_{6} + \mathrm{H}_{2}\mathrm{SO}_{4} \rightarrow \mathrm{C}_{6}\mathrm{H}_{5}\mathrm{SO}_{3}\mathrm{H} + \mathrm{H}_{2}\mathrm{O}\]
Understanding this first step requires recognizing the role of sulfuric acid, not just as a reagent, but also as a catalyst in sulfonation reactions.

The term 'desulfonation' refers to the reverse process of sulfonation, which means to remove the sulfonyl group from an organic molecule and restore the original compound. In the context of the original exercise, desulfonation involves heating benzene sulfonic acid with superheated steam under pressure. This reaction is endothermic, requiring the input of heat to proceed.

Desulfonation succeeds due to the conditions of high temperature and pressure that cause the sulfonyl group to leave, reverting to sulfuric acid, and regenerating the initial benzene molecule. This chemical rerouting is particularly useful when temporary attachment of the sulfonyl group is employed as a strategic step in the synthesis of more complex molecules.

The reaction from the solution is as follows:\[\mathrm{C}_{6}\mathrm{H}_{5}\mathrm{SO}_{3}\mathrm{H} + \mathrm{H}_{2}\mathrm{O} \rightarrow \mathrm{C}_{6}\mathrm{H}_{6} + \mathrm{H}_{2}\mathrm{SO}_{4}\]

Concentrated sulfuric acid is not just a mere reactant in chemical reactions; it often serves a dual purpose, both as an acid and a dehydrating agent. In the context of benzene sulfonation, sulfuric acid acts as a source of the electrophile when it reacts with itself to form sulfur trioxide (SO₃), which is the actual sulfonating agent.

In many industrial and laboratory settings, concentrated sulfuric acid is used due to its ability to participate in a wide variety of chemical transformations. Its high acidity and strong dehydrating nature make it a key player in electrophilic aromatic substitution reactions, like sulfonation, which can modify aromatic compounds to add functional groups that change their chemical properties.

Regenerating benzene is a process where benzene is recovered from its derivatives, in this case, from benzene sulfonic acid. The importance of this method lies in its ability to provide a clean, reversible path to modify benzene without permanently altering its structure.

From an educational standpoint, understanding the concept of regenerating benzene teaches students the reversibility of certain chemical reactions. It illustrates the concept of functional group interconversion—a common tactic in synthetic chemistry. By applying heat and pressure with steam, as the original problem states, benzene is obtained once again, proving the dynamic ability of chemical processes to both create and deconstruct complex molecules.