Question

which statement best describes a bronsted-lowry base?
it must accept protons to form a conjugate base.
it must accept protons to form a conjugate acid.
it must donate protons to form a conjugate base.
it must donate protons to form a conjugate acid.

Explanation:

According to the Brønsted - Lowry theory, a base is a proton ($H^+$) acceptor. When a Brønsted - Lowry base accepts a proton, it forms its conjugate acid. For example, in the reaction $NH_3 + H_2O
ightleftharpoons NH_4^+ + OH^-$, $NH_3$ (the base) accepts a proton from $H_2O$ to form $NH_4^+$ (its conjugate acid). The first option is wrong because accepting a proton forms a conjugate acid, not a conjugate base. The third and fourth options are wrong because bases accept protons, while acids donate protons.

Answer:

B. It must accept protons to form a conjugate acid.