# ClCN Lewis structure

ClCN (cyanogen chloride) has one chlorine atom, one carbon atom, and one nitrogen atom.

In ClCN Lewis structure, there is a single bond between carbon and chlorine atom, and a triple bond between carbon and nitrogen atom. The chlorine atom has three lone pairs, and the nitrogen atom has one lone pair.

Contents

## Steps

To properly draw the ClCN Lewis structure, follow these steps:

#1 Draw a rough sketch of the structure
#2 Next, indicate lone pairs on the atoms
#3 Indicate formal charges on the atoms, if necessary
#4 Minimize formal charges by converting lone pairs of the atoms
#5 Repeat step 4 if necessary, until all charges are minimized

Let’s break down each step in more detail.

### #1 Draw a rough sketch of the structure

• First, determine the total number of valence electrons

In the periodic table, chlorine lies in group 17, carbon lies in group 14, and nitrogen lies in group 15.

Hence, chlorine has seven valence electrons, carbon has four valence electrons, and nitrogen has five valence electrons.

Since ClCN has one chlorine atom, one carbon atom, and one nitrogen atom, so…

Valence electrons of one chlorine atom = 7 × 1 = 7
Valence electrons of one carbon atom = 4 × 1 = 4
Valence electrons of one nitrogen atom = 5 × 1 = 5

And the total valence electrons = 7 + 4 + 5 = 16

• Second, find the total electron pairs

We have a total of 16 valence electrons. And when we divide this value by two, we get the value of total electron pairs.

Total electron pairs = total valence electrons ÷ 2

So the total electron pairs = 16 ÷ 2 = 8

• Third, determine the central atom

We have to place the least electronegative atom at the center.

Since carbon is less electronegative than chlorine and nitrogen, assume that the central atom is carbon.

Therefore, place carbon in the center and chlorine and nitrogen on either side.

• And finally, draw the rough sketch

### #2 Next, indicate lone pairs on the atoms

Here, we have a total of 8 electron pairs. And two bonds are already marked. So we have to only mark the remaining six electron pairs as lone pairs on the sketch.

Also remember that chlorine is a period 3 element, so it can keep more than 8 electrons in its last shell. And both (carbon and nitrogen) are the period 2 elements, so they can not keep more than 8 electrons in their last shell.

Always start to mark the lone pairs from outside atoms. Here, the outside atoms are chlorine and nitrogen.

So for chlorine and nitrogen, there are three lone pairs, and for carbon, there is zero lone pair because all six electron pairs are over.

Mark the lone pairs on the sketch as follows:

### #3 Indicate formal charges on the atoms, if necessary

Use the following formula to calculate the formal charges on atoms:

Formal charge = valence electrons – nonbonding electrons – ½ bonding electrons

For chlorine atom, formal charge = 7 – 6 – ½ (2) = 0

For carbon atom, formal charge = 4 – 0 – ½ (4) = +2

For nitrogen atom, formal charge = 5 – 6 – ½ (2) = -2

Here, both carbon and nitrogen atoms have charges, so mark them on the sketch as follows:

The above structure is not a stable Lewis structure because both carbon and nitrogen atoms have charges. Therefore, reduce the charges (as below) by converting lone pairs to bonds.

### #4 Minimize formal charges by converting lone pairs of the atoms

Convert a lone pair of the nitrogen atom to make a new C — N bond with the carbon atom as follows:

### #5 Repeat step 4 (minimize charges again)

Since there are charges on carbon and nitrogen atoms, again convert a lone pair of the nitrogen atom to make a new C — N bond with the carbon atom as follows:

In the above structure, you can see that the central atom (carbon) forms an octet. And the outside atoms (chlorine and nitrogen) also form an octet. Hence, the octet rule is satisfied.

Also, the above structure is more stable than the previous structures. Therefore, this structure is the stable Lewis structure of ClCN.

Next: CH2S Lewis structure