Yes, some alcohols dissolve in water.
Does Alcohol Dissolve in Water? (EXPLAINED)
However, some variations of alcohol do not dissolve in water based on the way their chemical compounds attract or repel water.
This has to do with their polarities and the amounts of carbon chains and OH groups that make them up.
The remainder of this article will explain the key terms needed for understanding the topic and why some alcohols dissolve in water and why some do not.
To understand why some alcohols dissolve in water and some do not, we first need to understand basic terms like dissolution, solvent, and solubility.
Once we understand these terms, we can dive into how they relate to alcohol and water in our situation.
Dissolution is the action of breaking down a whole into pieces.
For our purposes, we are breaking down chemical bonds.
This term comes from the verb, dissolve.
To answer our question of whether or not alcohol dissolves in water, we must know that water is the dissolution of alcohol.
Another way we can categorize water in this scenario is by calling it a solvent, which is something (usually a liquid) that dissolves another substance.
Again, we are considering water to be the solvent and therefore the dissolution.
Solubility is the measure of something’s ability to dissolve.
In our situation, we are testing to see how alcohol dissolves in water, meaning we are looking for alcohol’s solubility.
The solubility of a substance can fluctuate based on three factors:
- When water is used as the solute, higher temperatures usually increase solubility. For example, sugar dissolves at any temperature of water, however, the warmer the water is, the quicker it dissolves.
- Pressure plays a bigger role in solubility when it comes to gases than it does for solids and liquids. This means it isn’t of concern for our particular situation.
- Polarity is the primary factor we will look at when determining if alcohol dissolves in water.
- When it comes to what will dissolve what, there is a general saying that goes “like dissolves like”. This means that the more closely related two substances’ chemical structures are the higher the solubility. Inversely, two substances with different polarities will not dissolve as easily or at all. Polarity plays an important role in determining why some alcohols dissolve in water and why some do not because of the difference in molecules that make up each substance.
Alcohol’s Solubility in Water
For our purposes, we will focus on seven primary types of alcohol; methanol, ethanol, propanol, butanol, pentanol, hexanol, and heptanol.
Of these seven, only three can dissolve in water; methanol, ethanol, and propanol.
Alcohol’s solubility is dependent on the strength of the molecules that make it up and how much they attract or repel the molecules that make water.
Chemically, alcohols are made up of carbon chains, which are nonpolar, and OH groups, which are polar.
Different types of alcohol have different amounts of carbon chains and OH groups.
Water, on the other hand, is polar.
This means that water is attracted to the OH groups in alcohol.
However, because of their polarities, the carbon chain repels the water, meaning the stronger of the two components of the alcohol, the carbon chain or the OH group, determines whether or not the alcohol is soluble.
Because each of the different alcohols carries different amounts of carbon chains and OH groups, some are able to dissolve in water while others are not.
Alcohol’s Ability to Dissolve in Water
Methanol, ethanol, and propanal all have weaker carbon chains within their chemical compounds than butanol, pentanol, hexanol, and heptanol.
This allows the OH groups and water to attract and therefore enhance the solubility of those three alcohols in water.
Because of the lack of strength in the carbon chain molecules, they can dissolve in water.
Butanol, pentanol, hexanol, and heptanol all have stronger carbon chains, meaning they repel the water, so it doesn’t break down the bond and therefore does not dissolve in water.
In this article, we learned some of the key terms needed to determine if alcohol dissolves in water.
From there, we learned how the varying levels of chemical compounds of carbon chains and OH groups within different alcohols either work with water to dissolve and break down the alcohol or repel the water and do not dissolve the alcohol.
The alcohols with stronger carbon chains do not dissolve in water, whereas the alcohols with weaker carbon chains do.
This is because of their polarities and how they either attract or repel water.
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