Why is hydrochloric acid (#HCl#) classified as a strong acid?

1 Answer
Oct 13, 2016

Answer:

Because of its dissociation in water.

Explanation:

The strength of an acid is determined by the extent of the following equilibrium:

#H-X + H_2O rightleftharpoons H_3O^+ + X^-#

If the equilibrium lies strongly to the right, #HX# is considered to be a strong acid. All the hydrogen halides, save #HF#, are considered to be exceptionally strong acids, and their aqueous solutions are stoichiometric in #H_3O^+#.