Identify which of the following will create a buffer system and provide justification for your answer.

• A. NaClO₄; because it is a salt
• B. HNO₃ and KOH; because it is composed of a strong acid and a strong base
• C. H₂SO₄; because it is a strong acid
• D. HNO₂ and NaNO₂; because it is composed of a weak acid and its conjugate base

Answer: (D)