Question

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

Answer 1

Hint: To solve this question we have to use the concept of bond length. Bond length is defined as the average distance present between the nuclei of the two bonded atoms in a molecule. Bond length is a type of transferable property of the bond between atoms of the fixed type, which is independent from the rest of the molecule.

Complete answer:
From your chemistry lessons you have learned about the bond length. Bond length is defined as the average distance present between the nuclei of the two bonded atoms in a molecule.
As we know that bond length is also related to bond order, we can say that if more electrons will take place in bond formation then the bond will be shorter. Bond length also has relation with bond strength and the bond dissociation energy as they are inversely proportional to each other. We can say that as the bond will be stronger it will be more shorter. Now, if we are asked to find the bond length between the two identical atoms then half of the bond length is equal to the covalent radius of any of the atoms.
So, there are some factors which affect the bond length and that are:
(i) The size of the atom increases as the bond length increases, For example the bond length of H-X where X is the halogen are given in the following order:
HI > HBr > HCl > HF
(ii) When multiplicity of bonds increases bond length decreases or we can say if the number or bonds between the same atom increases bond length decreases.
(iii) If the s-character will increase and shorter is the hybrid then the bond length will be shorter because s-orbitals are smaller in size.
(iv) Polar bonds are smaller than non-polar bonds

Therefore from the above discussion we can conclude that the lowest O-O bond length will be in ${{O}_{2}}{{F}_{2}}$ because all the electrons are pulling each other towards themselves and bond will be shorter.

Thus the correct option will be (A).

Note: Bond length is also called as the bond distance and bond length cannot be seen by the naked eyes. And the method that we have used is only used to find the longer or shorter bond length between the given molecules; it does not find their actual distance. Spectroscopy which is an advanced method is used to measure the actual distance.