Animated Solution for Chemistry - s and p-Block Elements: The product obtained from the electrolytic oxidation of acidified sulphate solutions, is

Imagine you have a concentrated solution of sulphuric acid ($50\%{\text{ H}}_2{\text{SO}}_4$). When you pass an electric current through this acidified sulphate solution, a fascinating chemical dance begins. The ions in the solution start migrating towards their respective electrodes. At the cathode, hydrogen ions (${\text{H}}^{+}$) gain electrons to bubble off as hydrogen gas. But the real magic happens at the anode.

At the anode, oxidation takes place. You might wonder, why doesn't water oxidize to give oxygen gas? Well, in a concentrated sulphate solution, the oxidation of bisulphate ions (${\text{HSO}}_4^{-}$) is kinetically favored over the oxidation of water.

Two bisulphate ions come together, lose two electrons, and form a new, larger molecule. The reaction can be written as:

Alternatively, starting from sulphuric acid:

The product formed is ${\text{H}}_2{\text{S}}_2{\text{O}}_8$, commonly known as Marshall's acid or peroxydisulphuric acid. The name itself gives away its secret: "peroxy" indicates the presence of a peroxide linkage ($-\text{O}-\text{O}-$), and "disulphuric" tells us there are two sulphur atoms involved.

If we look at the structure of Marshall's acid, we see two sulphuric acid-like units joined by an oxygen-oxygen single bond.

The structure is:

To match the options given in the question, we can group the atoms around each sulphur. On the left, we have an $\text{OH}$ group and two double-bonded oxygens attached to the sulphur, which gives us ${\text{HO}}_3\text{S}$. The same goes for the right side. These two groups are connected by the $-extO-extO-$ bridge.

Therefore, the condensed structural formula is beautifully written as ${\text{HO}}_3{\text{SOOSO}}_3\text{H}$.

This is a classic, high-yield concept from the p-block elements, highlighting how concentration and electrolytic conditions can lead to the formation of unique peroxy compounds.