Lewis Structure of H2O2 (With 6 Simple Steps to Draw!)

Ready to learn how to draw the lewis structure of H2O2?

Awesome!

Here, I have explained 6 simple steps to draw the lewis dot structure of H2O2 (along with images).

So, if you are ready to go with these 6 simple steps, then let’s dive right into it!

Lewis structure of H2O2 (or hydrogen peroxide) contains single bonds between the two Oxygen (O) atoms as well as between Oxygen (O) & Hydrogen (H) atoms. Both the Oxygen atoms have 2 lone pairs.

Let’s draw and understand this lewis dot structure step by step.

(Note: Take a pen and paper with you and try to draw this lewis structure along with me. I am sure you will definitely learn how to draw lewis structure of H2O2).

6 Steps to Draw the Lewis Structure of H2O2

Step #1: Calculate the total number of valence electrons

Here, the given molecule is H2O2 (or hydrogen peroxide). In order to draw the lewis structure of H2O2, first of all you have to find the total number of valence electrons present in the H2O2 molecule.
(Valence electrons are the number of electrons present in the outermost shell of an atom).

So, let’s calculate this first.

Calculation of valence electrons in H2O2

• For Hydrogen: 

Hydrogen is a group 1 element on the periodic table. ^[1]

Hence, the valence electron present in hydrogen is 1 (see below image).

• For Oxygen:

Oxygen is a group 16 element on the periodic table. ^[2]

Hence, the valence electron present in oxygen is 6 (see below image).

Hence in a H2O2 molecule, 

Valence electron given by each Hydrogen (H) atom = 1
Valence electrons given by each Oxygen (O) atom = 6
So, total number of Valence electrons in H2O2 molecule = 1(2) + 6(2) = 14

Step #2: Select the center atom (H is always outside)

While selecting the center atom, always put the least electronegative atom at the center.

(Remember: Fluorine is the most electronegative element on the periodic table and the electronegativity decreases as we move right to left in the periodic table as well as top to bottom in the periodic table). ^[3]

Here in the H2O2 molecule, if we compare the hydrogen atom (H) and oxygen atom (O), then hydrogen is less electronegative than oxygen. But as per the rule, we have to keep hydrogen outside.

So, both the oxygen atoms should be placed in the center and the remaining 2 hydrogen atoms will surround it.

Step #3: Put two electrons between the atoms to represent a chemical bond

Now in the above sketch of H2O2 molecule, put the two electrons (i.e electron pair) between the oxygen-oxygen atoms and oxygen-hydrogen atoms to represent a chemical bond between them.

These pairs of electrons present between the Oxygen atoms as well as between the Oxygen and Hydrogen atoms form a chemical bond, which bonds these atoms with each other in a H2O2 molecule.

Step #4: Complete the octet (or duplet) on outside atoms. If the valence electrons are left, then put the valence electrons pair on the central atom

Don’t worry, I’ll explain!

In the Lewis structure of H2O2, the outer atoms are hydrogen atoms.

So now, you have to check whether these hydrogen atoms are forming a duplet or not! (because hydrogen requires only 2 electrons to have a complete outer shell).

You can see in the above image that all the hydrogen atoms form a duplet.

Also, only 6 valence electrons of H2O2 molecule are used in the above structure.

But there are total 14 valence electrons in H2O2 molecule (as calculated in step #1).

So the number of electrons left to be kept on the central oxygen atoms = 14 – 6 = 8.

So let’s keep these eight electrons (i.e 4 electron pairs) on the central oxygen atoms.

Now, let’s move to the next step.

Step #5: Check whether the central atom has octet or not. If it does not have an octet, then convert the lone pair into double bond or triple bond

In this step, we have to check whether the central atoms (i.e oxygen) has an octet or not. 

In simple words, we have to check whether the central Oxygen (O) atoms are having 8 electrons or not.

As you can see from the above image, both the central atoms (i.e oxygen), have 8 electrons. So it fulfills the octet rule and the oxygen atoms are stable.

Step #6: Final step – Check the stability of lewis structure by calculating the formal charge on each atom

Now, you have come to the final step and here you have to check the formal charge on oxygen atoms (O) as well as hydrogen atoms (H).

For that, you need to remember the formula of formal charge;

Formal charge = Valence electrons – Nonbonding electrons – (Bonding electrons)/2

• For Oxygen:
  Valence electrons = 6 (as it is in group 16)
  Nonbonding electrons = 4
  Bonding electrons = 4
• For Hydrogen:
  Valence electron = 1 (as it is in group 1)
  Nonbonding electrons = 0
  Bonding electrons = 2

Formal charge	=	Valence electrons	–	Nonbonding electrons	–	(Bonding electrons)/2
O	=	6	–	4	–	4/2	=	0
H	=	1	–	0	–	2/2	=	0

So you can see above that the formal charges on oxygen as well as hydrogen are “zero”.

Hence, there will not be any change in the above structure and the above lewis structure of H2O2 is the final stable structure only.

Each electron pair (:) in the lewis dot structure of H2O2 represents the single bond ( | ). So the above lewis dot structure of H2O2 can also be represented as shown below.

Related lewis structures for your practice:
Lewis structure of F2
Lewis structure of CH2Cl2
Lewis structure of ClO2-
Lewis structure of ClO3-
Lewis structure of HCl

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