Question

The number of $P - O - P$ bridges in the structure of phosphorus pentoxide and phosphorus trioxide is respectively:
A.$6,6$
B.$5,5$
C.$5,6$
D.$6,5$

Answer 1

Phosphorus pentoxide and phosphorus trioxide are the two common oxides of phosphorus represented by the chemical formula $\left( {{P_4}{O_{10}}} \right)$ and $\left( {{P_4}{O_6}} \right)$ respectively. Phosphorus trioxide is represented as phosphorus hexoxide $\left( {{P_4}{O_6}} \right)$. The number of $P - O - P$ linkages or bridges can be easily calculated with the help of structure.

Complete step by step answer:
In the question, we are asked to calculate the number of $P - O - P$ bridges in the structure of phosphorus pentoxide and phosphorus trioxide. So, first, we will draw and analyze the structure of phosphorus pentoxide and phosphorus trioxide. So, now we will study the structure of the oxides one by one. Now let us consider the structure of phosphorus pentoxide $\left( {{P_4}{O_{10}}} \right)$. The structure is given below.

From the above structure of phosphorus pentoxide, we can observe that the total number of $P - O - P$ bridges in the structure of phosphorus pentoxide is $6$. Now we will consider the structure of phosphorus trioxide or hexoxide $\left( {{P_4}{O_6}} \right)$. The structure is given below.

Again, from the above structure of phosphorus trioxide or hexoxide, we can observe that the total number of $P - O - P$ bridges in the structure of phosphorus trioxide or hexoxide is $6$. So, we can conclude that the total number of $P - O - P$ bridges in the structure of phosphorus pentoxide and phosphorus trioxide are $6,6$ respectively.
Therefore, the correct option is (A).

Note:
The phosphorus pentoxide is a white crystalline solid and it is the anhydride of phosphoric acid as well as acts as a powerful dehydrating agent. On the other hand, phosphorus trioxide is a colorless solid and it is the anhydride of phosphorous acid.