Question

The correct chemical formula of red lead is:
A. $P{{b}_{3}}{{O}_{4}}$
B. $PbO$
C. $Pb{{O}_{2}}$
D. $P{{b}_{4}}{{O}_{3}}$

Answer 1

Hint: Think about the colours and properties of all the options given here and try to narrow down the possibilities using the more common lead compounds as reference.

Complete step by step answer:
Let us look at all the options and their properties to figure out which one of them is called red lead.
- $P{{b}_{3}}{{O}_{4}}$
This compound is known as lead tetroxide. It is bright red or orange in colour and is used in the production of dyes, paint primer, and also in the manufacture of batteries. It is a very good example of a mixed valence compound where lead has both +4 and +2 oxidation states.
- $PbO$
This compound is known as the lead oxide and is found in 2 forms, the silvery red coloured litharge and the yellow coloured massicot. Both of them are found in nature in the ore form and lead oxide is extracted from them.
-$Pb{{O}_{2}}$
This lead dioxide is a dark-brown inorganic compound that is insoluble in water. The oxidation state of lead is +4. It has many important applications in electrochemistry.
- $P{{b}_{4}}{{O}_{3}}$
This compound does not exist in a stable state naturally and has to be bonded to some other ligands or negatively charged ions to remain stable.
From all this information, we can deduce that the only compound that has a purely red colour is the lead tetraoxide. So, the answer to this question is ‘A. $P{{b}_{3}}{{O}_{4}}$’.

Note: Although the litharge ore is also red, it is more of a silvery red and is mostly found in ores. The finished final product is not as bright red as that of the lead tetraoxide. It is the tetraoxide that is most commonly known as red lead.