Question

What is the stock system name of \[{\text{PbC}}{{\text{l}}_{\text{2}}}\]?
A) Lead chloride
B) Lead (\[{\text{I}}\]) chloride (\[{\text{II}}\])
C) Lead (\[{\text{II}}\]) chloride
D) Plumbic chloride

Answer 1

Hint: Naming of chemical compounds generally include many rules formulated by different agencies. One of them is the IUPAC nomenclature. Stock system is another one used mainly for transition metal ions.

Complete step by step answer:
The Stock system of nomenclature is mainly used for metal cations which are mainly transition metals. Transition metals usually have more than one oxidation state due to their ability to show multiple valencies. This is because of the fact that the \[{\text{ns}}\]and \[{\text{np}}\]electrons can take part in reactions and share their electrons in order to have fully filled or half-filled stable orbitals.
In the Stock system of nomenclature, the oxidation state of the metal cation is represented by using Roman Numerals like I, II, III etc.
Here we have Lead as the metal which is having the atomic number as 82 and have the electronic configuration as follows;
\[{\text{Pb - [Xe] 4}}{{\text{f}}^{{\text{14}}}}{\text{5}}{{\text{d}}^{{\text{10}}}}{\text{6}}{{\text{s}}^{\text{2}}}{\text{6}}{{\text{p}}^{\text{2}}}\]
Here the 2 \[{\text{6s}}\] and 2 \[{\text{6p}}\] electrons can take part in reactions. So, lead has two oxidation states as \[{\text{ + 2}}\;{\text{and}}\;{\text{ + 4}}\]. So, we have to make clear the oxidation state of the element when it forms a compound. The Stock system of nomenclature is actually helping for it.
When we consider \[{\text{PbC}}{{\text{l}}_{\text{2}}}\], we can see that the element lead is in \[{\text{ + 2}}\] oxidation state.
So according to the stock system of nomenclature we can write the name of the compound as Lead (\[{\text{II}}\]) Chloride.

So, the correct answer is Option C.

Note: Lead chloride is usually a white crystalline substance. It is usually soluble in hot water whereas it is not soluble in cold water.

Stock systems of nomenclature are usually used for compounds containing transition metal cations. Transition metals are mainly d-block elements in the periodic table.