Animated Solution for Chemistry - s and p-Block Elements: Iodine reacts with concentrated ${\text{HNO}}_3$ to yield $Y$ along with other products. The oxidation state of iodine in $Y$, is

The reaction between halogens and nitric acid is a classic showcase of redox chemistry. When solid iodine ($I_2$) encounters concentrated nitric acid ($HN{O}_3$), a vigorous reaction ensues. Nitric acid, being a powerful oxidizing agent, doesn't just sit back; it aggressively strips electrons away from iodine.

Imagine dropping dark, lustrous crystals of iodine into a beaker of concentrated nitric acid. The mixture immediately begins to react, evolving dense, reddish-brown fumes of nitrogen dioxide ($N{O}_2$). But what happens to the iodine?

The balanced chemical equation for this transformation is:

In this reaction, the iodine is oxidized to form iodic acid, which has the chemical formula $HI{O}_3$. According to the problem statement, this is our mystery compound $Y$. Iodic acid is a white, water-soluble solid and is one of the most stable oxoacids of halogens.

Now that we have identified compound $Y$ as $HI{O}_3$, our next objective is to determine the oxidation state of the central iodine atom. To do this, we rely on a fundamental rule of chemistry: the sum of the oxidation states of all atoms in a neutral molecule must equal zero.

Let's assign the standard oxidation states to the other atoms in the molecule: Oxygen ($O$): In almost all of its compounds (except peroxides and fluorides), oxygen has an oxidation state of $-2$. Hydrogen ($H$): When bonded to non-metals, hydrogen has an oxidation state of $+1$.

Let the unknown oxidation state of iodine be $x$.

We can now set up a simple algebraic equation based on the molecular formula $HI{O}_3$:

Simplifying the terms, we get:

Moving the $5$ to the other side of the equation, we arrive at our final answer:

Thus, the oxidation state of iodine in iodic acid ($HI{O}_3$) is $+5$. This elegant calculation not only solves the problem but also highlights the profound oxidizing power of concentrated nitric acid, capable of elevating iodine from a $0$ oxidation state all the way to $+5$!