Question: is hf strong or weak?
Answer: HCl, HBr, and HI are all strong acids, whereas HF is a weak acid. The acid strength increases as the experimental pKa values decrease in the following order: HF (pKa = 3.1) < HCl (pKa = -6.0) < HBr (pKa = -9.0) < HI (pKa = -9.5).