If you are wondering about the polarity of H2O2, well, it is a polar molecule, and this blog post will help you understand why exactly. The polarity of the molecule helps us determine the chemical characteristics and other properties of the molecule. In this blog post, we help you understand the factors that help in deciding the H2O2 polarity along with lewis structure its properties, uses and formal charges.
Contents
Is H2O2 polar or nonpolar
One can determine whether the molecule is polar or nonpolar by looking at three factors for a molecule. Let’s go through these factors one by one to help you understand them better.
Electronegativities of the atoms
The polarity of any molecule largely depends upon the electronegativities of the atoms forming bonds in the molecule. The most electronegative atom always tries and pulls the shared valence electrons towards itself.
For H2O2, Oxygen atoms are the most electronegative ones as each Oxygen atom has an electronegativity value of 3.45. Whereas for the Hydrogen atom, it is around 2.20. The difference of electronegativities for Hydrogen and Oxygen atoms is relatively high, making the H-O bond polar. Generally, when the difference of electronegativities for any atom is higher than 0.5, their bond is considered polar.
Dipole moment in the molecule
As the Oxygen atom is more electronegative than the Hydrogen atom, it will try and pull the shared valence electrons towards itself. Because of this pull, there will be an uneven distribution where the direction of the moment will be towards the Oxygen atom. This uneven distribution of charges makes the regions around Oxygen partially negatively charged, and regions around Hydrogen atoms have partial positive charges.
As there are two poles formed in this molecule, it indicates that the molecule could be polar in nature. These dipole moments will be towards Oxygen atoms.
Molecular Shape
H2O2 molecule is a nonplanar and asymmetric molecule. It has a bent geometry due to the presence of two lone pairs of electrons on each Oxygen atom. Due to which the dipole moments in the molecule are not cancelled out. And hence there is a net dipole moment in the molecule, making H2O2 a polar molecule.
Formal Charges of H2O2
For calculating the formal charges for Hydrogen Peroxide, you can use our simple calculator or use this formula where:
Formal charge – valence electrons – unbonded electrons – ½ bonded electrons
For Oxygen, there are six valence electrons, four nonbonded pairs of electrons and four bonding pairs of electrons.
= 6- 4-4(½)
= 0
Hence the formal charges on the central atom are zero, and the formal charge for H2O2 is also zero.
Properties of H2O2
| Property | |
| Chemical name | Hydrogen Peroxide/ Dihydrogen Dioxide |
| Molar mass of H2O2 | 34.014 g/mol |
| State | Liquid ( at RT) |
| Boiling point of H2O2 | 150.2℃ |
| Melting point of H2O2 | -0.43℃ |
| Color of H2O2 | Pale blue |
| Density | 1.11 g/cm3 |
| Solubility | Miscible in water, soluble in water and ether |
Uses of H2O2
- Hydrogen peroxide is used as a potent oxidizing and bleaching agent.
- It is also used as an antiseptic as it can help heal wounds, cuts, etc.
- H2O2 is used in the production and synthesis of many chemicals.
- It is also used as a disinfectant and as a sanitizing product.
Concluding Remarks
Hydrogen Peroxide is a polar molecule because there is a net dipole moment in the molecule due to its bent shape. As this molecule has two partially charged molecules, it is polar in nature.
