Question

The lowest O-O bond length in the following molecule is:
A. ${{O}_{2}}{{F}_{2}}$
B. ${{O}_{2}}$
C. ${{H}_{2}}{{O}_{2}}$
D. ${{O}_{3}}$

Answer 1

Hint: As we know that bond length is the average distance in between the nuclei of the two bonded atoms in a molecule. It is basically a property of a bond between atoms that is transferable, and is independent from the rest of the molecule.

Complete answer:
We will discuss about the factors which can affect the bond length:
- First factor is atomic size. As the size of the atom increases, the bond length is also found to be increased.
- With the multiplicity of the bond that is with the increase in the number of bonds between same atoms, the bond length is found to decrease. Therefore, we can see that the order of bond length of carbon-carbon bonds is: $C\equiv C$< C=C < C-C
- Next factor is s-character. As we know that s-character will be greater if the size of s-orbital is smaller. And due to which shorter is the hybrid orbital, that results in the shorter bond length.
- Non-polar bond length is basically greater than polar bond length.
From the above discussion, we can say that ${{O}_{2}}{{F}_{2}}$ molecule has the lowest O-O bond length.

- Hence, we can conclude that the correct option is (a), that is the lowest O-O bond length is of ${{O}_{2}}{{F}_{2}}$ molecule.

Note: - We must note here that by this method we can’t find the actual distance, and can find only which bond length is shorter or longer.
- We can find the actual distance by using advanced techniques like spectroscopy.