# How is a strong acid different from a weak acid?

Mar 16, 2017

For the general acid, $H X$, in water, we write the equilibrium in the following way:
$H X \left(a q\right) + {H}_{2} O \left(l\right) r i g h t \le f t h a r p \infty n s {H}_{3} {O}^{+} + {X}^{-}$
For strong acids, $H X \left(X \ne F\right) , {H}_{2} S {O}_{4} , H N {O}_{3} , H C l {O}_{4}$ this equilibrium lies strongly towards the right, and their solutions are stoichiometric in ${H}_{3} {O}^{+}$. For weaker acids, $H F , H O A c , N {H}_{4}^{+}$, the equilibrium lies towards the left.