# What is the pKa of HCl (aq)?

Jun 17, 2018

$H X \left(a q\right) + {H}_{2} O \left(l\right) r i g h t \le f t h a r p \infty n s {H}_{3} {O}^{+} + {X}^{-}$
This site gives $p {K}_{a}$ values of $- 8.08$, $- 10.3$, and $- 10.7$ for $H C l$, $H B r$, and $H I$ respectively. The order of acidity is what we would expect on the basis of hydrogen-halogen overlap. The other hydrogen halide, $H F$, is NOT a strong Bronsted acid for what reason?