Question

How do you name ionic compounds with roman numerals?

Answer 1

Hint:As we know that the ionic compounds are those that contain a positively charged species called cation and a negatively charged species called anion. Ionic compounds are named where positive cation is named first which is followed by anion.

Complete step-by-step answer:
As we know that the chemical compounds are named according to the nomenclature given by IUPAC ruling. So, the ionic compounds are also named accordingly which involves the name of ionic compound by first stating the name of cation which is positively charged and then the anion which is negatively charge and in between these two species is written their oxidation state that is written inside the parentheses in roman numerals.

Also there is no space between while writing the element name and the parentheses. This is due to the metals possessing different oxidation states or valence. For instance: $F{e_2}{O_3}$ which is commonly called iron oxide but it is written as $iron(III)oxide$. The roman numerals inside the parentheses indicates that the iron is present in $ + 3$.

Also, we know that the roman numerals are used to determine the ionic charge of the cationic species in the compound such as iron which can form two types of ions and these are ferrous $(F{e^{2 + }})$ and ferric $(F{e^{3 + }})$. For example in $FeC{l_3}$ is ferric chloride or $iron(III)chloride$ where iron is present in ferric form. Thus, the above explanation describes the naming of ionic compounds.

Note: Always remember that certain elements like transition elements can form various types of ions and thus ionic compounds. And roman numerals like $I,II,III$ and so on are used in naming of these compounds to basically differentiate the ions.