Hydrofluoric acid is sparingly soluble in water but nevertheless donates a proton to…
CHEMISTRY · Multi-part · A Level · Chemistry · Acids and bases · Acids and bases
Problem
Hydrofluoric acid is sparingly soluble in water but nevertheless donates a proton to liquid water according to the equilibrium shown below.
HF(aq)+H2O(l)⇌F−(aq)+H3O+(aq)
Answer the following questions about this reaction.
(a) Identify the substance that functions as the proton donor and the substance that functions as the proton acceptor in the forward direction of the equilibrium.
(b) State the conjugate partner of each reactant and explain the criterion you used to assign these partners.
(c) Water is described as amphoteric. Using the reaction above, describe with particle-level reasoning how the amphoteric character of water is reflected in the equilibrium.
(d) Suppose a second equilibrium in the same solution is H3O+(aq)+F−(aq)⇌HF(aq)+H2O(l). Explain why the two equilibria can be considered the same chemical process written in opposite directions and discuss how this observation reinforces the concept of conjugate acid–base pairs.