So you have seen the above image by now, right?
Let me explain the above image in short.
P2O5 lewis structure has two Phosphorus atoms (P) at the center which is surrounded by five Oxygen atoms (O). The two Oxygen atoms (O) are double bonded while the other three Oxygen atoms (O) are single bonded with the Phosphorus atom (P).
If you haven’t understood anything from the above image of P2O5 lewis structure, then just stick with me and you will get the detailed step by step explanation on drawing a lewis structure of P2O5.
So let’s move to the steps of drawing the lewis structure of P2O5.
Steps of drawing P2O5 lewis structure
Step 1: Find the total valence electrons in P2O5 molecule
In order to find the total valence electrons in a P2O5 molecule, first of all you should know the valence electrons present in the phosphorus atom as well as oxygen atom.
(Valence electrons are the electrons that are present in the outermost orbit of any atom.)
Here, I’ll tell you how you can easily find the valence electrons of phosphorus as well as oxygen using a periodic table.
Total valence electrons in P2O5 molecule
→ Valence electrons given by phosphorus atom:
Phosphorus is group 15 element on the periodic table.  Hence the valence electrons present in phosphorus is 5.
You can see the 5 valence electrons present in the phosphorus atom as shown in the above image.
→ Valence electrons given by oxygen atom:
Oxygen is group 16 element on the periodic table.  Hence the valence electrons present in oxygen is 6.
You can see the 6 valence electrons present in the oxygen atom as shown in the above image.
Total valence electrons in P2O5 molecule = valence electrons given by 2 phosphorus atoms + valence electrons given by 5 oxygen atoms = 5(2) + 6(5) = 40.
Step 2: Prepare the rough sketch
For making the rough sketch, you have to remember that the atom which is less electronegative remains at the center.
Now here the given molecule is P2O5 and it contains phosphorus atoms (P) and oxygen atoms (O).
You can see the electronegativity values of phosphorus atom (P) and oxygen atom (O) in the above periodic table.
If we compare the electronegativity values of phosphorus (P) and oxygen (O) then the phosphorus atom is less electronegative.
So here, the phosphorus atoms (P) are the center atom and the oxygen atoms (O) are the outside atoms.
(Note: Don’t get confused in the above sketch. It looks as if the oxygen atom is the center atom, but it is not so. The phosphorus atoms have less electronegativity and hence they are the center atoms and the oxygen atoms are the surrounding atoms.)
Step 3: Connect each atoms by putting an electron pair between them
Now in the P2O5 molecule, you have to put the electron pairs between the phosphorus (P) & oxygen (O) atoms.
This indicates that these atoms are chemically bonded with each other in a P2O5 molecule.
Step 4: Make the outer atoms stable
Now in this step, you have to check the stability of the outer atoms.
Here in the sketch of P2O5 molecule, you can see that the outer atoms are oxygen atoms.
These outer oxygen atoms are forming an octet and hence they are stable.
Also, in step 1 we have calculated the total number of valence electrons present in the P2O5 molecule.
The P2O5 molecule has a total 40 valence electrons and all these valence electrons are used in the above sketch of P2O5.
Hence there are no remaining electron pairs to be kept on the central atom.
So now let’s proceed to the next step.
Step 5: Check the octet on the central atom. If it does not have octet, then shift the lone pair to form a double bond or triple bond.
In this step, you have to check whether the phosphorus atoms (P) are stable or not.
In order to check the stability of the central phosphorus (P) atoms, we have to check whether they are forming an octet or not.
Unfortunately, the phosphorus atoms are not forming an octet here. Phosphorus has only 6 electrons and they are unstable.
Now to make these phosphorus atoms stable, you have to shift the electron pairs from the outer oxygen atoms so that the phosphorus atoms can have 8 electrons (i.e octet).
After shifting these electron pairs, the central phosphorus atoms will get 2 more electrons and thus their total electrons will become 8.
You can see from the above picture that the phosphorus atoms are forming an octet as they have 8 electrons.
Hence, this is the most stable lewis structure of P2O5.
In the above lewis dot structure of P2O5, you can also represent each bonding electron pair (:) as a single bond (|). By doing so, you will get the following lewis structure of P2O5.
I hope you have completely understood all the above steps.
For more practice and better understanding, you can try other lewis structures listed below.
Try (or at least See) these lewis structures for better understanding:
|C2Br4 Lewis Structure
|TeBr2 Lewis Structure
|AsF5 Lewis Structure
|HI Lewis Structure
|PO3- Lewis Structure
|BBr3 Lewis Structure
Jay is an educator and has helped more than 100,000 students in their studies by providing simple and easy explanations on different science-related topics. He is a founder of Pediabay and is passionate about helping students through his easily digestible explanations.
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