Answer:
- The addition of a small amount of HCl to a solution containing fluoride ions and hydrogen fluoride will cause the equilibrium shift to the production of more hydrogen fluoride.
Step-by-step explanation:
The solution containing fluoride ions and hydrogen fluoride (a weak acid) may be chemically represented by this equilibrium equation:
- F⁻ (aq) + H⁺ (aq) ⇄ HF (aq)
The HCl, a strong acid, added will ionize in water according to this chemical equation:
- HCl (aq) → H⁺ (aq) + Cl⁻ (aq)
Then, following Le Chatelir's principle, the addtion of H⁺ ions coming from the HCl dissociation, will increase the concentration of H⁺ in the solution, driving to the consumption of some F⁻ ions, and the production of more HF acid. This is a shift of the equilbrium toward the HF side.