The formal charge on the carbon atom in the following structure `underset(* *)overset(* *)O=C=underset(* *)overset(* *)O` is …………………….

Explanation

Structure I of `CO_(2) - underset(* *)overset(* *)O=C + underset(* *) overset(* *)O`
Formal charge on carbon `=N_(v)-[N_(l)+(N_(b))/(2)]=4-[0+(8)/(2)]=4-4=0`
Formal charge on oxygen `= N_(v)-[N_(l)+(N_(b))/(2)]=6-[4+(4)/(2)]=6-6=0`
Structure II of `CO_(2) - :O-=C-underset(* *)overset(* *)O:`
Formal charge on carbon `= N _(v)-[N_(l)+(N_(b))/(2)]=4-[0++(8)/(2)]=4-4=0`
Formal charge on singly bonded oxygen `= N_(v)-[N_(l)+(N_(b))/(2)]=6-[6+(2)/(2)]= 6-7=-1`
Formal charge on triply bonded oxygen `=N_(v)-[N_(l)+(N_(b))/(2)]=6-[2+(6)/(2)]=6-5=+1`
A structure in which all formal charges are zero is preferred over the one with non-zero charges. In case of `CO_(2)` structure, structure I is preferred over the structure II as it has zero formal charge for all the atoms.