Question

Which one is represented correctly in terms of Stock notation?
A. $FeC{{l}_{3}}: Iron(II) chloride$
B. $N{{O}_{2}}^{+}: Nitrogen~Peroxide$
C. $N{{O}_{2}}: Nitrogen (IV) oxide$
D. $N{{O}_{2}}: Nitrogen~Dioxide$

Answer 1

To answer this, use the rules of Stock notation i.e. stating the oxidation state by using Roman numerals within the parenthesis. Look after each option and check which one follows the rule of Stock’s nomenclature.

Complete Solution :
So, let’s see what Stock Nomenclature is.
- Stock nomenclature is a nomenclature for inorganic compounds, which is a widely used system of chemical nomenclature that was developed by the German chemist Alfred Stock and was first published in $1919$. So, in the stock system of nomenclature, the oxidation states of some or all of the elements in a compound are indicated in parentheses by Roman numerals.

So, now let us see how an ionic or a molecular compound is named by using Stock nomenclature;
The four steps to name a compound using Stock notation includes:
- Add an “ide” to the end of the second compound’s name and change the name of that compound, so it ends with ‘ide’. For example, chlorine is to be changed to chloride, oxygen to oxide and so on.
- For ionic compounds with transition metals, insert a roman numeral after the name of the metal to indicate the oxidation state. So, denote with the roman numerals like $I,II,III$ and so on.
- Use prefix when required in a molecular compound as there are no ionic charges to balance out in these compounds. For example, in ${{N}_{2}}{{O}_{5}}$ the name will be dinitrogen pentoxide, as it has two nitrogen in its first name.
So, coming to the options given, we have $FeC{{l}_{3}}$ and $N{{O}_{2}}$.
$FeC{{l}_{3}}$ will be known by the name $Iron(III) chloride$, as iron has an oxidation state of $+3$ and chlorine is changed to chloride while, $N{{O}_{2}}$ will be known by $Nitrogen(IV) oxide$, as here nitrogen has an oxidation state of $+4$and oxygen is changed to oxide.
So, the correct answer is “Option C”.

Note: Possible mistake could be, you may get confused with the oxidation state and the prefix to be added within the parenthesis. First find out the oxidation state of the first element and if the first element present is only one then use “-mono” as prefix, for two atoms, use “-di” and so on.