There are three types of polarity and two types of covalent bonds. The three types are- polar, non-polar and ionic. These are classified on the basis of the force between the chemical bonds which allows attraction of two specific elements to each other. The number of covalent bonds a element can form is determined by the number of vacant spaces of electrons in the elements valance shell.
Non-Polar vs Polar Covalent Bonds
The main difference between Non-Polar and Polar Covalent Bonds is that non-polar covalent bonds are bonds between elements that have the same electronegativity whereas polar covalent bonds are bonds between elements that have different electronegativity.
The non-polar covalent bonds and polar covalent bonds fall under the classification of covalent bonds. They occur in non-metal and two different types of elements. This classification also tells the sharing and distribution of electrons in the two different elements and also the resulting electronegativity between them.
The formation of bonds occur when the elements combine and some of the electrons from one element transfers to another. This transfer can either result in equal sharing of electrons or unequal sharing of electrons. The type of bond that will form between these elements is determined by the electronegativity difference between them.
Comparison Table Between Non-Polar and Polar Covalent Bonds
| Parameters of Comparison | Non-polar Covalent Bonds | Polar Covalent Bonds |
| Definition | Non-polar covalent bonds are bonds between elements that have the same electronegativity. | Polar covalent bonds are bonds between elements that have different electronegativity. |
| Electron cloud | The electron clouds in these molecules are not distorted. | The electron cloud in these molecules are distorted. |
| Charge build up | There is no charge build up in these elements. | There is a charge build up at the poles of these elements. |
| Dipole bond | Non-polar covalent bonds have no dipole moment. | Polar covalent bonds have a dipole moment. |
| Force between molecules | There are weak Van der Waal’s forces of attraction between the molecules. | There are more stronger forces of attraction than the Van der Waal’s forces between the molecules. |
| Melting and boiling points | These compounds have lower melting and boiling points than polar covalent bond molecules. | These compounds have higher melting and boiling points. |
| Conducting electricity | These compounds do not conduct electricity. | These compounds conduct electricity in aqueous solution. |
What is Non-Polar Covalent bond?
When electrons are shared equally between two atoms a chemical bond is formed which is called a non-polar covalent bond. This is why, the electrons shared of each atom in these molecules are the same. Also, the electronegativity between these atoms is almost negligible.
In other words, both the atoms have similar electronegativity and no charge separation between them. This type of bond can also be formed when the atoms sharing a polar bond arrange in such such a manner that the electric charges between them cancels out each other. These type of bonds occur between different atoms or identical atoms that are non-metals.
What is Polar Covalent bond?
The bond which forms between two atoms whose electrons are not evenly distributed are called polar covalent bonds. Polar covalent bonds can be said to be a dividing line between the formation of an ionic bond and a pure covalent bond. Due to this, there is always an electric dipole moment in these molecules where the two ends are relatively negative or positive.
They are generally formed between two atoms that are non-metal who have different electronegativity. The compounds who have this bond can exist as solids due to there is a greater force of interactions. Also, the melting and boiling points of these compounds are very high. They can conduct electricity if dissolved in an aqueous solution. These compounds are easily soluble in polar solvents like water.
Main Differences Between Non-Polar and Polar Covalent Bonds
- Non-polar covalent bonds are bonds between elements that have the same electronegativity between them whereas polar covalent bonds are bonds between elements that have different electronegativity between them.
- Non-polar covalent bonds have weak Van der Waal’s forces of attraction between them while polar covalent bonds have stronger forces of attraction than Van der Waal’s forces between them.
- The electron clouds in non-polar covalent bond molecules are not distorted whereas the electron clouds in polar covalent bond molecules are distorted.
- Non-polar covalent bond compounds have lower melting and boiling points than polar covalent bond molecules.
- Non-polar covalent bond compounds do not conduct electricity whereas polar covalent bond molecules can conduct electricity in aqueous solutions.
- Non-polar covalent bonds molecules have no dipole moment whereas polar covalent bond molecules have a dipole moment.
- There is no charge build-up in non-polar covalent bond molecules while there is a charge build-up at poles in polar covalent bond molecules.
Conclusion
Both the non-polar covalent bonds and polar covalent bonds are a type of covalent bond. The main difference is the atoms needed for their formation. When electrons are shared equally between two atoms, a non-polar covalent bond is formed whereas when electrons are not evenly distributed between two atoms, a polar covalent bond is formed. Non-polar covalent bonds have weak Van der Waal’s forces of attraction between them.
Polar covalent bonds have more stronger forces than the Van der Waal’s forces like hydrogen bonding and others between them. Polar covalent bond compounds also have a higher melting and boiling points than non-polar covalent bond compounds due to the greater force of attraction between the atoms of the molecules. Non-polar covalent bonds occur between different atoms and even in identical atoms that are non-metals.
Polar covalent bonds are generally formed between two atoms that are non-metal with different electronegativity. Also, polar covalent bond compounds can conduct electricity in aqueous solution due to the high mobility of it’s atoms whereas non-polar covalent bond compounds cannot conduct electricity in any state.
References
- https://pubs.rsc.org/en/content/articlehtml/1994/p2/p29940002149
- https://www.sciencedirect.com/science/article/pii/S0022283602004655