For each of the following structures,

1. Draw a Lewis structure; fill in any nonbonding electrons.

2. Calculate the formal charge on each atom other than hydrogen. All are electrically neutral except as noted.

Solution 34SP :

Step 1:

Here, we have to draw a Lewis structure and fill in any nonbonding electrons and also calculate the formal charge on each atom other than hydrogen.

Formal charge is calculated using the formula :

Formal charge = Valence electrons - Nonbonding electrons -

It is also calculated using a shortcut formula :

Formal charge = Valence electrons - (Number of bonds + Number of dots)

Step 2:

The given compound is Diazomethane(CH2N2). This compound has resonance forms. The lewis structure and the formal charge of the atoms are as shown below :

Now, let’s calculate the formal charge for the atoms in the 1st structure :

Formal charge = Valence electrons - ( Number of bonds + Number of dots)

Now, let’s calculate the formal charge for C :

C = 4 - (4 + 0)= 0

Now, let’s calculate the formal charge for 1st N atom :

N = 5 - (4 + 0) = +1

Thus 1st nitrogen atom in the chain has formal charge of +1 and it is represented in the diagram above.

Now, let’s calculate the formal charge for 2nd N atom :

N = 5 - (2 + 4 ) = -1.

Hence, 2nd nitrogen atom in the chain has formal charge of -1 and it is represented in the diagram above.

Now, let’s calculate the formal charge for the atoms in the 2nd structure :

Formal charge = Valence electrons - ( Number of bonds + Number of dots)

Now, let’s calculate the formal charge for C :

C = 4 - (3 + 2)= -1

Thus carbon atom in the chain has formal charge of -1 and it is represented in the diagram above.

Now, let’s calculate the formal charge for 1st N atom :

N = 5 - (4 + 0) = +1

Thus 1st nitrogen atom in the chain has formal charge of +1 and it is represented in the diagram above.

Now, let’s calculate the formal charge for 2nd N atom :

N = 5 - (3 + 2 ) = 0.

Step 3 :

The lewis structure and the formal charge of the atoms are as shown below :

Now, let’s calculate the formal charge for the atoms here :

Formal charge = Valence electrons - ( Number of bonds + Number of dots)

Now, let’s calculate the formal charge for 1st C atom :

C = 4 - (4 + 0)= 0

Now, let’s calculate the formal charge for 2nd C atom :

C = 4 - (4 + 0) = 0

Now, let’s calculate the formal charge for 3rd C atom :

C = 4 - (4 + 0) = 0

Now, let’s calculate the formal charge for N atom :

N = 5 - (4 + 0) = +1

Now, let’s calculate the formal charge for O atom :

O = 6 - (1 + 6 ) = -1.

Hence, oxygen atom in the chain has formal charge of -1 and it is represented in the diagram above.