We have been thinking about how one molecule could interact with another molecule of the same compound to form a liquid or a solid. What about two different compounds?

What is Miscibility ?

The degree to which one liquid can mix with another is associated with the term called “miscibility.” The term is most often applied to liquids but also applies to solids and gases. Miscible means to be able to mix. This clearly depicts what miscible liquids are, they are the liquids that can mix with each other.

For example, water and ethanol are miscible because they mix in all proportions.

What is immiscibility ?

By contrast, substances are said to be immiscible if there are certain proportions in which the mixture does not form a solution. For one example, oil is not soluble in water, so these two solvents are immiscible.