According to Brønsted-Lowry theory, how is a base defined?

In Brønsted-Lowry theory, a base is defined as a substance that accepts protons (H⁺ ions) during a chemical reaction. This definition focuses on the transfer of protons between substances, distinguishing it from the Arrhenius definition, which is more limited.

When a base accepts a proton, it typically reacts with an acid (which is defined as a substance that donates protons). The resulting interaction leads to the formation of conjugate acids and bases. For example, when ammonia (NH₃) accepts a proton, it becomes ammonium (NH₄⁺), illustrating the core concept of proton acceptance inherent in Brønsted-Lowry bases.

Utilizing this perspective allows for a broader understanding of acid-base interactions, accommodating reactions that do not necessarily involve hydroxide ions or the formation of aqueous solutions. In this way, the Brønsted-Lowry definition aligns with many diverse chemical processes occurring in both biological systems and industrial applications.