Leaving Certification (LC) Chemistry 2025 – 400 Free Practice Questions to Pass the Exam

A substance that accepts protons is classified as a base. This concept is grounded in the Brønsted-Lowry theory of acids and bases, which defines acids as proton donors and bases as proton acceptors. When a base interacts with an acid, it accepts a proton (H+) from the acid, which leads to the formation of a conjugate acid.

In addition to the Brønsted-Lowry framework, there is another common definition from Lewis theory, which describes bases as electron pair donors. However, the hallmark characteristic of a base in the context of proton acceptance remains consistent. Understanding this distinction is key to grasping the behavior of various chemical substances in reactions.

The other choices represent different classes of compounds: acids, oxidizing agents, and salts, which do not fit the proton-accepting definition. For instance, acids release protons, while oxidizing agents accept electrons. Salts, on the other hand, are compounds formed from the neutralization reaction between an acid and a base. Therefore, recognizing that a compound that accepts protons is specifically a base is crucial for mastering acid-base chemistry.