What must an Arrhenius acid contain?

1 Answer
Aug 6, 2018

Answer:

An Arrhenius acid is a substance whose aqueous solutions give rise to hydrogen ions or protons.

Explanation:

And thus we may identify as an acid a species that undergoes the following reaction with water...

#HX stackrel(H_2O)rarrH^+ + X^-#

The acidium ion, #H^+#, is an hypothetical species, and is more commonly represented as hydronium ion, i.e. #H_3O^+#, i.e.

#HX(aq) + H_2O(l) rarrH_3O^+ + X^-#

Both #H^+#, and #H_3O^+# are labels of convenience (the latter is more common these days. The actual acidium ion is PROBABLY a cluster of 3-4 water molecules with an EXTRA proton, #H^+#...to give #H_7O_3^(+)# or #H_9O_4^(+)#. The proton is presumed to tunnel from cluster to cluster, we write #H_3O^+# without loss of generality.

And so an Arrhenius acid must contain an hydrogen ion that can be transferred to solvent....