Question

How do I write $Sn{\left( {N{O_3}} \right)_2}$ in ionic formula?

Answer 1

The ionic formula is the representation of a chemical species as charged ions. The charged ions contain the counter ions in the form of cations and anions.

Complete step by step answer:
The given compound is Tin(II)nitrate. The compound is composed of one tin ($Sn$) atom and two nitrate molecules. The tin is the central atom in this compound which is flanked between two nitrate ions or molecules.
The compound is a neutral molecule having no net charge. Thus the charge of the ions which consists of the compounds balances each other. In general the cation is written first followed by the anion. The charge on each ion corresponds to the subscript of the subsequent ion.
As an example for a compound ${A_x}{B_y}$, the cation is $A$ having a net charge of $+ y$and the anion is $B$ having a net charge of $-x$. Thus the charge of the ions balances each other as the molecule ${A_x}{B_y}$ is a neutral compound.
We know that $Sn$is an element in the periodic table with atomic number $50$ and electronic configuration $\left[ {Kr} \right]4{d^{10}}5{s^2}5{p^2}$. The valence shell of tin is $5$ and has four valence electrons. The two electrons in the valence $5s$ shell are inert due to the inert pair effect. Thus tin shows a valency of $2$ and loses these electrons for bond formation. The oxidation state of $Sn$ is $+ 2$.
On the other hand the nitrate ion is a negatively charged species carrying a unit negative charge and it is represented as $N{O_3}^ -$ ions. The negative charge on nitrate ion is visualized from the nitric acid with chemical formula $HN{O_3}$. The nitric acid dissociates as ${H^ + }$ and $N{O_3}^ -$ ions.
Thus the ionic formula of $Sn{\left( {N{O_3}} \right)_2}$ is written as $S{n^{2 + }}N{O_3}^ -$.

Note:
The individual oxidation state of each of the atoms in a molecule is evaluated with the help of the valency of other elements present in a molecule. This helps in writing the ionic formula of a molecule.