What is the term for a substance that readily mixes with water?

The term for a substance that readily mixes with water is "miscible." When two liquids are described as miscible, it means they can be mixed in any ratio without separating into two phases. This property is important in various scientific and engineering applications, such as in solution chemistry or when combining different liquids in processes.

In contrast, "soluble" refers to a solute's ability to dissolve in a solvent, often associated with solid substances dissolving in liquids. While often used interchangeably in casual settings, "soluble" is more about solids, while "miscible" specifically addresses the mixing of liquids.

The terms "immiscible" and "insoluble," on the other hand, describe substances that do not mix well with water. Immiscible substances will separate into distinct layers when combined, whereas insoluble substances do not dissolve at all in the solvent, typically leading to sedimentation rather than mixing.