Finding the concentration of an acid

Question

25.0 mL of a solution of unknown concentration of fluorous acid is titrated by 20 mL of a 0.07 M solution of ammonium hydroxide. What is the concentration of the acid?

Answer 1

Thanks : Reaction : HFO₂ + (NH₄⁺,HO^-) --> H₂O + FO₂^- + NH₄⁺.

Equivalence : n(HFO₂) = n((NH₄⁺,HO^-) so C(HFO₂)xV(HF) = C(NH₄⁺,HO^-)xV(NH₄⁺,HO^-) and the concentration of HFO₂ is : C(HFO₂) = 0.07x20/25 = 0.056 M.