Question

In which of the following cases $M - F$ bond has partial double bond character where M is the central atom.
A) $O{F_2}$
B) $P{F_3}$
C) $CC{l_3}F$
D) All of these.

Answer 1

We know that the Partial double bonds are caused by resonance during a structure, which is that, the transfer of pi electrons from one site to another. They are said to be partial because the structure can resonate, or flip, between two or more conformations. Of those conformations, a minimum of one will feature a covalent bond between the 2 atoms of interest and a minimum of one will feature one bond.

Complete answer:
We have to remember that there is no any vacant orbital in oxygen and Carbon in which other atoms like fluorine and chlorine can donate their lone pair. Therefore there is no any partial double bond character. Therefore, the option A, C and D is incorrect. But in phosphorus there will be empty d-orbitals and therefore will show partial double bond character.
Hence option B is correct.

Additional note:
We realize that the bond order is the quantity of electrons sets shared between two molecules in the development of the bond. The amount of energy important to break a bond is called bond separation energy. Hence more noteworthy the bond request more prominent is the bond energy.
$\text{Bond Order} \propto {\text{Bond energy}} \propto \dfrac{1}{\text{Bond Length}}$
As the bond order diminishes, the bond diminishes as well. On account of that triple connections between molecules are more limited than twofold bonds since it requires more energy to totally break each of the three bonds than to break two. In any case, triple bonds are likewise more grounded than twofold bonds. The equivalent is with the twofold bonds and single bonds.

Note:
We must remember that the stability of the peptide linkage is because of the resonance of amides. With resonance, the nitrogen is in a position to donate its lone pair of electrons to the carbonyl carbon and push electrons from the carbonyl covalent bond towards the oxygen, forming the oxygen anion. This resonance effect is extremely stabilizing because the electrons are often delocalized over multiple atoms, with one especially stable resonance structure containing the highly electronegative oxygen as an anion. The partial covalent bond leads to the amide group being planar thus causing them to require either the cis or trans conformation.