Question

Which of the following is incorrect about ${{H}_{4}}{{P}_{2}}{{O}_{5}}$?
A. It contains P in +5 oxidation state
B. It is a dibasic acid
C. It is strongly reducing in nature
D. It contains one $P-O-P$ bond

Answer 1

Hint: ${{H}_{4}}{{P}_{2}}{{O}_{5}}$ is known by the name pyro phosphorus acid which is generally colorless or odorless in nature. ${{H}_{4}}{{P}_{2}}{{O}_{5}}$ is soluble in water, diethyl ether, and ethyl alcohol. This acid is somewhat corrosive but not kept in the category of toxic acids.

Complete step by step answer:
We have to choose the incorrect statement about ${{H}_{4}}{{P}_{2}}{{O}_{5}}$ this can be explained on the basis of discussion of each point.
A. It contains P in +5 oxidation state: Oxidation state of P i.e. Phosphorus is calculated as this way in ${{H}_{4}}{{P}_{2}}{{O}_{5}}$; Hydrogen have -1 oxidation state, oxygen carries -2 charge and overall charge on the compound is zero so $(-1)\times 4+x\times 2+(-2)\times 5 = 0$ where we find the value of x = +3 so this statement is not true.
B. It is dibasic acid: ${{H}_{4}}{{P}_{2}}{{O}_{5}}$ is dibasic acid this can be explained by the structure of ${{H}_{4}}{{P}_{2}}{{O}_{5}}$ which is as follows:

Hydrogen atoms which are attached with the oxygen atom contribute to the basicity here we can see that 2 hydrogens atoms are attached so it is dibasic in nature.
C. It is strongly reducing in nature: Given statement is true because it can easily donate electrons and become oxidized in nature.
D. It contains one $P-O-P$ bond: The given statement is true; we can easily see in its structure that it has one $P-O-P$ bond.
So, the correct answer is “Option A”.

Note: The anhydrous form of pyrophosphoric acid crystallizes in two polymorphs and this compound has no particular applications in main industries and pyrophosphoric acid is also known by the other name called diphosphoric acid.