KrCl4 Lewis structure

KrCl₄ has one krypton atom and four chlorine atoms.

In KrCl₄ Lewis structure, there are four single bonds around the krypton atom, with four chlorine atoms attached to it. Each chlorine atom has three lone pairs, and the krypton atom has two lone pairs.

Alternative method: Lewis structure of KrCl₄

Contents

Rough sketch

First, determine the total number of valence electrons

In the periodic table, krypton lies in group 18, and chlorine lies in group 17.

Hence, krypton has eight valence electrons and chlorine has seven valence electrons.

Since KrCl₄ has one krypton atom and four chlorine atoms, so…

Valence electrons of one krypton atom = 8 × 1 = 8
Valence electrons of four chlorine atoms = 7 × 4 = 28

And the total valence electrons = 8 + 28 = 36

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

Second, find the total electron pairs

We have a total of 36 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 = 36 ÷ 2 = 18

Third, determine the central atom

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

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

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

And finally, draw the rough sketch

KrCl4 Lewis Structure (Step 1) — Rough sketch of KrCl₄ Lewis structure | Image: Learnool

Lone pair

Here, we have a total of 18 electron pairs. And four Kr — Cl bonds are already marked. So we have to only mark the remaining fourteen electron pairs as lone pairs on the sketch.

Also remember that krypton is a period 4 element, so it can 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 krypton, there are two lone pairs.

Mark the lone pairs on the sketch as follows:

KrCl4 Lewis Structure (Step 2) — Lone pairs marked, and got the stable Lewis structure of KrCl₄ | Image: Learnool

Formal charge

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

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

For krypton atom, formal charge = 8 – 4 – ½ (8) = 0

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

Here, both krypton and chlorine atoms do not have charges, so no need to mark the charges.

Final structure

The final structure of KrCl₄ comprises a central krypton atom linked to four chlorine atoms through single covalent bonds. In this arrangement, the krypton atom utilizes an expanded octet to accommodate twelve valence electrons, which includes four bonding pairs and two lone pairs. Each chlorine atom satisfies the octet rule by maintaining three lone pairs of its own. This specific configuration is preferred because it results in formal charges of zero for every atom in the molecule, representing the most energetically favorable state for the molecule. Consequently, this electronic pattern serves as the definitive and most accurate Lewis representation for KrCl₄.

Next: PS₃^– Lewis structure

External video

How to Draw the Lewis Dot Structure for KrCl4: Krypton tetrachloride – YouTube • Wayne Breslyn

External links

Deep

Learnool.com was founded by Deep Rana, who is a mechanical engineer by profession and a blogger by passion. He has a good conceptual knowledge on different educational topics and he provides the same on this website. He loves to learn something new everyday and believes that the best utilization of free time is developing a new skill.