Question

In bisulphate ion, the formal charge on the sulfur atom is:
A. $+1$
B. $+2$
C. $+4$
D. $+6$

Answer 1

Formal charge of an atom in a molecule can be found by the relation: $formal\,charge=valence\text{ }electrons-\left( non-bonding\text{ }valance\text{ }electrons \right)-\dfrac{\left( bonding\text{ }electrons \right)}{2}$
Using the above relation, find the formal charge on the sulfur atom in bisulphate ion.

Complete step by step answer:
We know that the relation to find the formal charge mathematical can be expressed as shown below:
$formal\,charge=valence\text{ }electrons-\left( non-bonding\text{ }valance\text{ }electrons \right)-\dfrac{\left( bonding\text{ }electrons \right)}{2}$
The structure of the bisulphate ion is as follows:

In which the middle atom is the sulfur atom.
The valence electrons of the sulfur atom is = 06 electrons;
The non-bonding valence electrons of the sulfur atom in the above molecule is = 0 electrons;
The bonding valence electrons of the sulfur atom in the above molecule is = 08 electrons.
Put all these values in the above formula and calculate the formal charge
After substituting all the values in the above relation we obtain
$formal\,charge=6-\left( 0 \right)-\dfrac{8}{2}\text{ = +2 }$

Therefore the required formal charge on the sulfur atom in the bisulphate molecule is $+2$
Hence option (B) is the correct answer.

Note: Formal charge can be defined as the charge assigned to an atom in a molecule, assuming that electrons in all chemical bonds are shared equally between atoms, regardless of the relative electronegativity.
The formal charge on an atom in a molecule reflects the electron count associated with the atom compared to the isolated neutral atom.