Definition

Noun: A homogeneous mixture where water is the solvent. An aqueous solution is one in which a substance (the solute) is dissolved in water, forming a single, clear liquid phase.

Usage

This term is used primarily in scientific contexts, especially chemistry, biology, and environmental science, to specify that water is the dissolving medium. It distinguishes solutions made with water from those made with other solvents (e.g., alcoholic solutions, oily solutions).

Examples

• The salt dissolved completely, forming a clear aqueous solution.
• In the lab, we prepared an aqueous solution of sodium hydroxide for the experiment.
• Many biological processes occur within the aqueous solutions inside cells.

Advanced Usage

• "Aqueous solution" vs. "Solution": Using "aqueous" is precise; a general "solution" could use any solvent. For example, "a solution of iodine" is ambiguous (it could be in alcohol or water), while "an aqueous solution of iodine" is specific.
• Concentration in Aqueous Solutions: The term is often used when discussing concentration, e.g., "a 0.1 molar aqueous solution of HCl."

Variants and Related Words

• Aqueous (adjective): Of, relating to, or resembling water; made with, by, or from water. (e.g., an aqueous humor in the eye; aqueous minerals).
• Solvent (noun): The liquid in which a solute is dissolved to form a solution (water is the solvent in an aqueous solution).
• Solute (noun): The substance that is dissolved in a solvent.
• Hydrophilic (adjective): Having a tendency to mix with, dissolve in, or be wetted by water; these substances often form aqueous solutions easily.

Synonyms

• Water-based solution
• Water solution

Antonyms

• Non-aqueous solution (a solution where the solvent is not water, e.g., an organic solution).
• Anhydrous mixture (a mixture containing no water).

Related Phrases / Collocations

• To prepare an aqueous solution: The standard phrase for making one.
• Concentrated aqueous solution: An aqueous solution with a high amount of solute relative to solvent.
• Dilute aqueous solution: An aqueous solution with a low amount of solute relative to solvent.
• Aqueous phase: Used in chemistry to describe the water-based layer in a mixture that separates from a non-aqueous (e.g., organic) layer.

Noun

1. a solution in water