Question

What is the name of ${{P}_{4}}{{O}_{6}}$?

Answer 1

The molecules which consist of only two elements covalently bonded to each other are called binary covalent molecules. Covalent inorganic molecules are generally named by using a method similar to that for ionic compounds and by using proper prefixes to show the number of atoms of each element in the molecular formula.

Complete answer:
${{P}_{4}}{{O}_{6}}$ is an inorganic chemical compound in which phosphorus atoms are covalently bonded with chlorine atoms and to name inorganic covalent compound, we must follow certain number of steps which are as follows:
Step-1: The element which is present at the left position from the other element in the periodic table will be named first. If both the elements are from the same group, then the element closer to the bottom of the column will be named first. In the case of ${{P}_{4}}{{O}_{6}}$, the phosphorus atom is placed at a position left from oxygen atom and hence, phosphorus atom will be named first.
Step-2: The second element in the molecule is assumed to be a mono-atomic ion in an ionic compound (even if it is not) and named by adding a suffix $-ide$ along with the base name of the element. In the case of ${{P}_{4}}{{O}_{6}}$, the oxygen atom will be named as oxide.
Step-3: If more than one atom of any element is present in the molecule, then use the appropriate prefixes like di, tri, etc. along with the name of the element. In the case of ${{P}_{4}}{{O}_{6}}$, four atoms of phosphorus and six atoms of oxygen are present in the molecule. So, the prefix used with phosphorus and oxygen will be tetra and hexa respectively.
Thus, we can conclude that the name of the given compound i.e., ${{P}_{4}}{{O}_{6}}$ is tetraphosphorus hexaoxide.

Note:
It is important to note that although the molecular formula of ${{P}_{4}}{{O}_{6}}$ suggests the name tetraphosphorus hexaoxide. But it is also named as phosphorus trioxide because it precedes the knowledge for the molecular structure of the compound and is a more commonly used name.