The Story Behind the Unique Polarity of Ethanol
Ethanol is a unique and very versatile substance as it takes many forms and has very distinct characteristics. As a very interesting substance, ethanol has many sides and can be used as a fuel, an additive, and many more. One of the most important information on ethanol is whether ethanol is polar or not.
Is ethanol polar or non polar?
The fact is, ethanol is known as a polar substance. Its polarity allows its molecules to stick together better, which is why ethanol is miscible with water and many other organic solvents.
Water, as it happens, is one of the most polar molecules present, so when the polar molecules of ethanol encounters water, their molecules stick together, and the water molecules completely carry the alcohol molecules away. This characteristic is unique compared to other hydrocarbons such as ethane and oil, which do not dissolve in water. This is why oil floats in water and does not mix with it, whereas ethanol is a great polar solvent for many other substances. This is also why ethanol takes its liquid form in room temperature whereas ethane remains in its gas form.
What’s unique about ethanol is that while other molecules are very polar and some are not polar at all, ethanol is midway between very polar and not polar. One end of the molecule is not polar, similar to ethane, while the other end is highly polar like water.
Due to the polarity of ethanol and its miscibility with water, if you add 50 mL of ethanol to 50 mL of water, you will get 96 mL of liquid instead of 100 mL due to the different sizes of the molecules of water and ethanol.
But what is the real story behind the unique ethanol polarity?
Why is ethanol a polar molecule?
As a chemical, ethanol belongs to the hydroxyl group, or its OH group. Its hydroxyl group gives it its polarity. This is because the hydroxyl group is composed of the polar covalent bond between the hydrogen atom and the oxygen atom. Since the hydrogen atom has a slightly positive charge while the oxygen atom has a slightly negative charge, ethanol has a negative charge and is therefore a polar substance.
However, ethanol is still less polar than water, which is known as the most polar solvent available. Its lower polarity gives it a lower boiling point than water, and also makes it easy to separate from water through heating at temperatures of around 70 degrees Celsius. When heated, the ethanol part evaporates whereas the water stays in its liquid form. However, as it condenses, the evaporated alcohol cools and turns back into its liquid form.
What does ethanol polarity mean?
Since ethanol is a polar substance, it is known to be a very stable substance at room temperature. This is what makes it an ideal fuel choice for vehicles.