Question

 What is the formal charge on the chloride atom in the oxyacid $HOCl{{O}_{2}}$if it contains a single bond?
A. $-2$
B. $-1$
C. $+1$
D. $+2$

Answer 1

 Hint: The formal charge of an atom says about the charge that is assigned to it in a molecule and it can be calculated if you know about the number of valence electrons, number of nonbonding electrons or lone pair of electrons and the total number of sigma bonds which is shared in covalent bond of that atom in its ground state. Try to draw the Lewis structure of the molecule given and by using the formula of formal charge, you will get your answer.

Complete step by step answer:  
The charge assigned to an atom in a molecule is known as formal charge. This is calculated by the formula:
$FC=V-N-B$
Where, FC is the formal charge of the atom that is to be calculated,
              V is the number of valence electrons of an atom in its ground state,

              N is the number of nonbonding electrons or the number of lone pair of electrons, and

              B is the number of sigma bonds shared by that atom.
So, the Lewis structure of $HOCl{{O}_{2}}$ can be shown as:

Thus, as per the given question we have to find out the formal charge of chlorine atom that is bonded with a single bond. So, we can see that chlorine is single bonded with an oxygen atom and chlorine has two lone pairs of nonbonding electrons. Also, we can see that it has three sigma bonds with oxygen. As we know, the valence electrons of chlorine are seven.
Thus, the chlorine will have,
$V=7$
$N=2$
$B=3$
Therefore, the formal charge of chlorine atom that is single bonded will be,
Using the above formula,
$FC=7-2-3=2$
Thus, the answer we got is in positive form. So, the answer will be $+2$.
Hence, the correct option is D.

Note: The valence electrons are the electrons which are present in the outermost shell of an atom and these can take part in chemical bonding. The non-bonding electrons are those electrons which do not take part in the chemical bonding and they are also referred to as lone pairs of electrons.