Determine the formal charge of each element in the following:

(a) \({\rm{HCl}}\)

(b) \({\rm{C}}{{\rm{F}}_{\rm{4}}}\)

(c) \({\rm{PC}}{{\rm{l}}_{\rm{3}}}\)

(d) \({\rm{P}}{{\rm{F}}_{\rm{5}}}\)

A formal charge (\({\rm{F}}{\rm{.C}}{\rm{.}}\)or\({\rm{q}}\)) is the charge attributed to an atom in a molecule in the covalent perspective of bonding, assuming that electrons in all chemical bonds are shared equally among atoms, regardless of relative electronegativity.

a)

To find the Formal charge use the formula –

Formal Charge \({\rm{ = }}\) \({\rm{(}}\)Number of valence electrons on atom) \({\rm{ - }}\) (non-bonded electrons \({\rm{ + }}\) Bonding electrons\({\rm{)}}\).

Formal Charge for\({\rm{H}}\) is:

\(\begin{aligned}&= \left( {\rm{1}} \right){\rm{ - }}\left( {{\rm{0 + 1}}} \right)\\&= 0\end{aligned}\)

Formal Charge for\({\rm{Cl}}\)is:

\(\begin{aligned}&= \left( 7 \right){\rm{ - }}\left( {{\rm{6 + 1}}} \right)\\&= 0 \end{aligned}\)

The formal charge for \({\rm{HCl}}\) is found below –

Therefore, the formal charge for \({\rm{H}}\) and\({\rm{Cl}}\) is \(0\).

(b)

To find the Formal charge use the formula –

Formal Charge\({\rm{ = }}\) \({\rm{(}}\)Number of valence electrons on atom) \({\rm{ - }}\) (non-bonded electrons \({\rm{ + }}\)Bonding electrons\({\rm{)}}\).

Formal Charge for\({\rm{C}}\) is:

\(\begin{aligned}&= \left( {\rm{4}} \right){\rm{ - }}\left( {{\rm{0 + 4}}} \right)\\&= 0\end{aligned}\)

Formal Charge for \({\rm{F}}\) is:

\(\begin{aligned}&= \left( 7 \right){\rm{ - }}\left( {{\rm{6 + 1}}} \right)\\&= 0\end{aligned}\)

The formal charge for \({\rm{C}}{{\rm{F}}_{\rm{4}}}\) is found below –

Therefore, the formal charge for\({\rm{C}}\)and\({\rm{F}}\)is\(0\).

(c)

To find the Formal charge use the formula –

Formal Charge\({\rm{ = }}\) \({\rm{(}}\)Number of valence electrons on atom) \({\rm{ - }}\) (non-bonded electrons \({\rm{ + }}\)Bonding electrons\({\rm{)}}\).

Formal Charge for \({\rm{P}}\) is:

\(\begin{aligned}&= \left( {\rm{5}} \right){\rm{ - }}\left( {{\rm{2 + 3}}} \right)\\&= 0\end{aligned}\)

Formal Charge for \({\rm{Cl}}\)is:

\(\begin{aligned}&= \left( 7 \right){\rm{ - }}\left( {{\rm{6 + 1}}} \right)\\&= 0\end{aligned}\)

The formal charge for\({\rm{PC}}{{\rm{l}}_{\rm{3}}}\) is found below –

Therefore, the formal charge for\({\rm{P}}\) and \({\rm{Cl}}\) is \(0\).

(d)

To find the Formal charge use the formula –

Formal Charge\({\rm{ = }}\) \({\rm{(}}\)Number of valence electrons on atom)\({\rm{ - }}\) (non-bonded electrons \({\rm{ + }}\) Bonding electrons\({\rm{)}}\).

Formal Charge for \({\rm{P}}\) is:

\(\begin{aligned}&= \left( {\rm{5}} \right){\rm{ - }}\left( {{\rm{0 + 5}}} \right)\\&= 0\end{aligned}\)

Formal Charge for\({\rm{F}}\)is:

\(\begin{aligned}&= \left( 7 \right){\rm{ - }}\left( {{\rm{6 + 1}}} \right)\\&= 0\end{aligned}\)

The formal charge for\({\rm{P}}{{\rm{F}}_{\rm{5}}}\) is found below –

Therefore, the formal charge for\({\rm{P}}\) and\({\rm{F}}\)is\(0\).