What is the conjugate acid of HF?

The conjugate acid of H₂F⁺ ion. When HF acts as a base, it accepts a proton (H⁺) to become H₂F⁺ ion. Inversely, H₂F⁺ ion loses a proton to become HF.

HF + H⁺ ⇌ H₂F⁺

H₂F⁺

HF + H+ =====> H2F+

H2F+