Which statement describes a base?

Which statement describes a base?

• A. Has a conjugate acid and could gain another proton
• B. Has a conjugate base and could donate a proton
• C. Donates a proton in water
• D. Is Always a Weak Base

Answer: (A)

In Brønsted–Lowry terms, a base is a substance that accepts a proton, forming its conjugate acid. This means a base is defined by its ability to take up a proton and, in doing so, become the species’s conjugate acid. The statement captures this idea by describing a base as having a conjugate acid and the capacity to gain a proton to form that conjugate acid. Donating a proton in water describes an acid, not a base. Saying a base has a conjugate base would apply to the conjugate partner after the acid donates a proton, not to the defining property of a base itself. And bases can be either strong or weak; saying a base is always a weak base is incorrect.

In Brønsted–Lowry terms, a base is a substance that accepts a proton, forming its conjugate acid. This means a base is defined by its ability to take up a proton and, in doing so, become the species’s conjugate acid. The statement captures this idea by describing a base as having a conjugate acid and the capacity to gain a proton to form that conjugate acid.

Donating a proton in water describes an acid, not a base. Saying a base has a conjugate base would apply to the conjugate partner after the acid donates a proton, not to the defining property of a base itself. And bases can be either strong or weak; saying a base is always a weak base is incorrect.