Liquid is one of the three phases in which all matter can exist. Liquids have properties different from solids and gases. Most of the properties of a liquid are in between the properties of solids and gases. We can classify liquids into two categories based on their miscibility, i.e., the ability of two substance to mix and form a homogenous mixture.
What are Miscible Liquids
Miscible liquids are liquid substances that can mix in all proportions to form a homogeneous solution. In other words, miscible liquids form when two liquids fully dissolve in each other at any concentration. The term miscibility describes this ability to mix with each other, and this term is mostly used with liquids, but it may have applications regarding solids and gases as well.
For example, miscibility of water and ethanol is common where water and ethanol act as miscible liquids by mixing with each other in all possible proportions. When considering organic compounds, the weight percentage of hydrocarbon chains tend to determine the miscibility of the organic compound with water. E.g. ethanol contains two carbon atoms where 1-butanol contains four carbon atoms (both are alcohols), but ethanol is miscible with water while 1-butanol is not.
Often, the miscibility of liquids is determined optically. If the two liquids combine and make a clear liquid, then the two liquids are miscible with each other. If the combined liquids appear cloudy after mixing, then those liquids are immiscible with each other.
What are Immiscible Liquids?
Immiscible liquids are incapable of mixing and attaining homogeneity. This is the opposite of miscible liquids. E.g. oil and water are immiscible with each other. The resulting liquid mixture appears cloudy, which indicates the immiscibility of liquids in all proportions.
When considering organic compounds and water, they become immiscible if the number of carbon atoms in the hydrocarbon chain is high. The higher the number of carbon atoms, the more nonpolar the compound becomes; thus, it cannot dissolve in water because water is a polar solvent.
Usually, the miscibility of liquids is determined optically. However, if the refraction indices of two liquids are similar, then the combination of those two liquids can give a clear solution which gives an incorrect determination about the miscibility of the liquids.
What is the Difference Between Miscible and Immiscible Liquids?
Miscible and immiscible liquids are categorized based on their miscibility. Miscible liquids are liquid substances that can mix in all proportions to form a homogeneous solution while immiscible liquids are liquids that are incapable of mixing and attaining homogeneity. Therefore, the key difference between miscible and immiscible liquids is that miscible liquids form a homogenous solution, whereas immiscible liquids form a heterogeneous solution.
Furthermore, miscible liquids mix with each other in all possible proportions while immiscible liquids do not mix with each other in all proportions. Moreover, another difference between miscible and immiscible liquids is that liquids with the same polarity can be miscible while liquids with different polarity are immiscible.
The below infographic summarizes the differences between miscible and immiscible liquids in tabular form.
Summary – Miscible vs Immiscible Liquids
There are two types of liquids as miscible and immiscible liquids, depending on the miscibility. The key difference between miscible and immiscible liquids is that miscible liquids form a homogenous solution, whereas immiscible liquids form a heterogeneous solution.
1. “Miscibility.” Wikipedia, Wikimedia Foundation, 17 Dec. 2020, en.wikipedia.org/wiki/Miscibility.