Final answer:
The strongest conjugate base among the provided acids, HCl, HF, H₂SO₄, and HNO₃, is F-, the conjugate base of HF (hydrofluoric acid), as HF is the weakest acid compared to the other given strong acids. The strength of a conjugate base is inversely related to the strength of its acid.
Step-by-step explanation:
The student's question asks which of the following acids has the strongest conjugate base: A. HCl (hydrochloric acid) B. HF (hydrofluoric acid) C. H₂SO₄ (sulfuric acid) D. HNO₃ (nitric acid). To identify the acid with the strongest conjugate base, one must understand that the strength of a conjugate base is inversely related to the strength of its acid. Strong acids have very weak conjugate bases, while weak acids have stronger conjugate bases.
From the provided list, HCl is a strong acid, thus its conjugate base (Cl-) is very weak. Both H₂SO₄ and HNO₃ are also classified as strong acids, which means their conjugate bases are quite weak as well. HF, while often listed with the strong acids, is not as fully dissociated in solution as the others, and its conjugate base (F-) will be the strongest among those listed because it has a slight ability to accept a proton. The high electronegativity of fluorine allows the conjugate base F- to stabilize the negative charge more effectively than the other halides, which makes F- a relatively stronger base.