SbF3 Lewis structure

SbF₃ (antimony trifluoride) has one antimony atom and three fluorine atoms.

In SbF₃ Lewis structure, there are three single bonds around the antimony atom, with three fluorine atoms attached to it. Each fluorine atom has three lone pairs, and the antimony atom has one lone pair.

Alternative method: Lewis structure of SbF₃

Rough sketch

• First, determine the total number of valence electrons

In the periodic table, antimony lies in group 15, and fluorine lies in group 17.

Hence, antimony has five valence electrons and fluorine has seven valence electrons.

Since SbF₃ has one antimony atom and three fluorine atoms, so…

Valence electrons of one antimony atom = 5 × 1 = 5
Valence electrons of three fluorine atoms = 7 × 3 = 21

And the total valence electrons = 5 + 21 = 26

Learn how to find: Antimony valence electrons and Fluorine valence electrons

• Second, find the total electron pairs

We have a total of 26 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 = 26 ÷ 2 = 13

• Third, determine the central atom

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

Since antimony is less electronegative than fluorine, assume that the central atom is antimony.

Therefore, place antimony in the center and fluorines on either side.

• And finally, draw the rough sketch

Lone pair

Here, we have a total of 13 electron pairs. And three Sb — F bonds are already marked. So we have to only mark the remaining ten electron pairs as lone pairs on the sketch.

Also remember that antimony is a period 5 element, so it can keep more than 8 electrons in its last shell. And fluorine is a period 2 element, so it can not keep more than 8 electrons in its last shell.

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

So for each fluorine, there are three lone pairs, and for antimony, there is one lone pair.

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 antimony atom, formal charge = 5 – 2 – ½ (6) = 0

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

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

Final structure

The final structure of SbF₃ features a central antimony atom connected to three fluorine atoms through single covalent bonds. Within this layout, the antimony atom satisfies the octet rule by maintaining one lone pair alongside its three bonding pairs. Each fluorine atom similarly fulfills its octet by retaining three lone pairs of its own in addition to the single shared bond. This arrangement is the most stable because it results in formal charges of zero for all atoms involved, representing the most energetically favorable state for the molecule. Accordingly, this specific electronic distribution serves as the definitive and most accurate Lewis representation of antimony trifluoride.

Next: AsO₃^3- Lewis structure

External video

• How to Draw the Lewis Dot Structure for SbF3: Antimony trifluoride – YouTube • Wayne Breslyn

External links

• https://lambdageeks.com/sbf3-lewis-structure/
• https://www.chegg.com/homework-help/questions-and-answers/draw-lewis-structure-sbf3-window-answer-questions-follow-include-overall-ion-charges-forma-q38800377
• https://www.bartleby.com/questions-and-answers/draw-the-lewis-structure-for-sbf3-in-the-window-below-and-then-answer-the-questions-that-follow.-.-d/d7fe6cd3-c4a7-4b02-89e5-44b46ff2b50f
• https://oneclass.com/homework-help/chemistry/7042771-lewis-structure-sbf3.en.html