NCl2- Lewis structure

NCl₂^– has one nitrogen atom and two chlorine atoms.

In NCl₂^– Lewis structure, there are two single bonds around the nitrogen atom, with two chlorine atoms attached to it. Each chlorine atom has three lone pairs, and the nitrogen atom has two lone pairs.

Also, there is a negative (-1) charge on the nitrogen atom.

Alternative method: Lewis structure of NCl₂^–

Rough sketch

• First, determine the total number of valence electrons

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

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

Since NCl₂^– has one nitrogen atom and two chlorine atoms, so…

Valence electrons of one nitrogen atom = 5 × 1 = 5
Valence electrons of two chlorine atoms = 7 × 2 = 14

Now the NCl₂^– has a negative (-1) charge, so we have to add one more electron.

So the total valence electrons = 5 + 14 + 1 = 20

Learn how to find: Nitrogen valence electrons and Chlorine valence electrons

• Second, find the total electron pairs

We have a total of 20 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 = 20 ÷ 2 = 10

• Third, determine the central atom

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

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

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

• And finally, draw the rough sketch

Lone pair

Here, we have a total of 10 electron pairs. And two N — Cl bonds are already marked. So we have to only mark the remaining eight electron pairs as lone pairs on the sketch.

Also remember that nitrogen is a period 2 element, so it can not keep more than 8 electrons in its last shell. And chlorine is a period 3 element, so it can keep more than 8 electrons in its last shell.

Always start to mark the lone pairs from outside atoms. Here, the outside atoms are chlorines.

So for each chlorine, there are three lone pairs, and for nitrogen, there are two lone pairs.

Mark the lone pairs on the sketch as follows:

Formal charge

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

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

For nitrogen atom, formal charge = 5 – 4 – ½ (4) = -1

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

Here, the nitrogen atom has a charge, so mark it on the sketch as follows:

Final structure

The final structure of NCl₂^– has a central nitrogen atom connected to two chlorine atoms through single covalent bonds. In this configuration, the nitrogen atom satisfies the octet rule by forming two bonding pairs and retaining two lone pairs. Each chlorine atom also fulfills its octet by maintaining three lone pairs of its own alongside the single shared bond. This setup is the most stable because it results in a formal charge of -1 on the nitrogen atom and zero on each chlorine atom, representing the most energetically favorable distribution for the ion. As a result, this specific electronic distribution serves as the definitive and most accurate Lewis representation of this ion.

To complete the representation, draw square brackets around the entire Lewis structure and place a “-” or “-1” sign as a superscript outside the upper right bracket. This notation signifies that the negative charge is a property of the whole ion.

Next: AsCl₅ Lewis structure

External video

• How to Draw the Lewis Dot Structure for NCl2 – – YouTube • Wayne Breslyn

External links

• https://www.chegg.com/homework-help/questions-and-answers/lewis-structure-ncl2-q9384605
• https://brainly.com/question/22563695