The equilibrium constant for the reaction below has the value Ka = 3.5 x 10^-4. In this reaction, the stronger Brønsted-Lowry acid is ________ and the weaker Brønsted-Lowry acid is ________. HF(aq) + H2O(l) ⇌ H3O+(aq) + F-(aq)

• A. H3O+ and F-
• B. F- and H2O
• C. HF and H3O+
• D. H2O and HF

Answer: (C)

Verified step by step guidance

1. Identify the acids and bases in the given chemical equation. In the reaction HF(aq) + H2O(l) ⇌ H3O+(aq) + F-(aq), HF and H3O+ are the acids, while H2O and F- are the bases.
2. Understand the concept of Brønsted-Lowry acids and bases. A Brønsted-Lowry acid is a substance that donates a proton (H+), and a Brønsted-Lowry base is a substance that accepts a proton.
3. Analyze the equilibrium constant (Ka) value. The equilibrium constant provides information about the strength of the acids involved in the reaction. A smaller Ka value indicates a weaker acid, while a larger Ka value indicates a stronger acid.
4. Compare the acids in the reaction. HF is the acid on the reactant side, and H3O+ is the acid on the product side. Since the equilibrium constant Ka = 3.5 x 10^-4 is relatively small, HF is the stronger acid compared to H3O+.
5. Conclude which acids are stronger and weaker. Based on the analysis, HF is the stronger Brønsted-Lowry acid, and H3O+ is the weaker Brønsted-Lowry acid in this reaction.