What is an aqueous solution called that yields hydrogen ions when ionized?

An aqueous solution that yields hydrogen ions when ionized is classified as an acid. This characteristic is fundamental to the definition of acids in chemistry, particularly according to the Brønsted-Lowry theory, which states that acids are proton donors. When an acid ionizes in water, it releases hydrogen ions (H⁺), which can increase the concentration of these ions in the solution, thereby affecting the solution's pH and leading to acidic properties.

The importance of this concept is reflected in various biological and chemical processes, where the presence of hydrogen ions plays a crucial role in reactions, enzyme activity, and maintaining the proper pH levels for cellular functions. Understanding the behavior of acids is essential in biotechnology, particularly in applications involving fermentation, metabolic pathways, and biochemical assay optimization.