Well, let me tell you about hexane. Hexane is a molecule that consists of six carbon atoms and 14 hydrogen atoms. It’s a pretty simple molecule, but it has some interesting properties. One of those properties is that it is non-polar.
Now, let’s talk about polarity. Polarity refers to the distribution of electrons in a molecule. In a polar molecule, the electrons are not evenly distributed, creating regions of partial positive and partial negative charges. This happens when there is a significant difference in electronegativity between the atoms in the molecule.
In the case of hexane, the electronegativity difference between the hydrogen and carbon atoms is very small, only 0.4 on the Pauling scale. Electronegativity is a measure of an atom’s ability to attract electrons towards itself. Since the difference in electronegativity is so small, the electrons in hexane are shared almost equally between the carbon and hydrogen atoms. This means that there are no regions of partial positive or partial negative charges in the molecule, making it non-polar.
To further explain this, let’s look at the carbon-carbon bonds in hexane. Carbon and carbon have the same electronegativity, so the electrons in the carbon-carbon bonds are shared equally. This means that there are no regions of partial positive or partial negative charges along the carbon-carbon backbone of the molecule.
Now, let’s talk about the intermolecular forces that hold hexane molecules together in the liquid state. Hexane molecules are held together by London dispersion forces, also known as van der Waals forces. These forces occur between all molecules, regardless of their polarity. In the case of hexane, the London dispersion forces are the dominant intermolecular forces.
London dispersion forces arise from temporary fluctuations in electron distribution, creating temporary dipoles in the molecule. These temporary dipoles induce dipoles in neighboring molecules, resulting in an attractive force between the molecules. The strength of London dispersion forces increases with the size of the molecules and the surface area available for interaction.
In the case of hexane, the carbon atoms form a long, straight chain, which maximizes the surface area available for interaction. This leads to stronger London dispersion forces between hexane molecules. However, since hexane is non-polar, there are no permanent dipoles in the molecule, and the London dispersion forces are the only intermolecular forces present.
I hope this explanation helps you understand why hexane is non-polar. It’s all about the small electronegativity difference between the carbon and hydrogen atoms, which results in a molecule with no regions of partial positive or partial negative charges. And in the liquid state, hexane molecules are held together by London dispersion forces.