PBr4+ Lewis structure

PBr₄⁺ has one phosphorus atom and four bromine atoms.

In PBr₄⁺ Lewis structure, there are four single bonds around the phosphorus atom, with four bromine atoms attached to it, and on each bromine atom, there are three lone pairs.

Also, there is a positive (+1) charge on the phosphorus atom.

Alternative method: Lewis structure of PBr₄⁺

Rough sketch

• First, determine the total number of valence electrons

In the periodic table, phosphorus lies in group 15, and bromine lies in group 17.

Hence, phosphorus has five valence electrons and bromine has seven valence electrons.

Since PBr₄⁺ has one phosphorus atom and four bromine atoms, so…

Valence electrons of one phosphorus atom = 5 × 1 = 5
Valence electrons of four bromine atoms = 7 × 4 = 28

Now the PBr₄⁺ has a positive (+1) charge, so we have to subtract one electron.

So the total valence electrons = 5 + 28 – 1 = 32

Learn how to find: Phosphorus valence electrons and Bromine valence electrons

• Second, find the total electron pairs

We have a total of 32 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 = 32 ÷ 2 = 16

• Third, determine the central atom

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

Since phosphorus is less electronegative than bromine, assume that the central atom is phosphorus.

Therefore, place phosphorus in the center and bromines on either side.

• And finally, draw the rough sketch

Lone pair

Here, we have a total of 16 electron pairs. And four P — Br bonds are already marked. So we have to only mark the remaining twelve electron pairs as lone pairs on the sketch.

Also remember that phosphorus is a period 3 element, so it can keep more than 8 electrons in its last shell. And bromine is a period 4 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 bromines.

So for each bromine, there are three lone pairs, and for phosphorus, there is zero lone pair because all twelve electron pairs are over.

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 phosphorus atom, formal charge = 5 – 0 – ½ (8) = +1

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

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

Final structure

The final structure of PBr₄⁺ consists of a central phosphorus atom connected to four bromine atoms through single covalent bonds. In this configuration, the phosphorus atom satisfies the octet rule by forming four bonding pairs. Each bromine 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 phosphorus atom and zero on each bromine 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 species.

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 positive charge is a property of the whole ion.

Next: TeCl₂ Lewis structure

External video

• How to Draw the Lewis Dot Structure for PBr4 + – YouTube • Wayne Breslyn

External links

• https://lambdageeks.com/pbr4-lewis-structure/
• https://homework.study.com/explanation/draw-the-lewis-structure-for-pbr4-plus-and-determine-its-electron-and-molecular-geometries.html
• https://www.chegg.com/homework-help/questions-and-answers/lewis-diagram-pbr4-electron-pair-geometry-around-p-atom-pbr4-lone-pair-s-around-central-at-q21882167
• https://www.numerade.com/ask/question/to-answer-the-questions-interpret-the-following-lewis-structure-for-pbr4-br-r-r-r-br-1-for-the-central-phosphorus-atom-the-number-of-lone-pairs-the-number-of-single-bonds-the-number-of-doubl-47997/
• https://www.answers.com/Q/What_is_the_total_number_of_valence_electrons_in_the_Lewis_structure_of_PBr4_plus