Question #b85c7

1 Answer
May 1, 2017

In water, the hydronium ion is CLEARLY the acid..........

Explanation:

Water is well known to undergo the following reaction, so-called #"auto-protolysis"#, or #"self-ionization"#:

#2H_2OrightleftharpoonsH_3O^+ + HO^-#

These ionic species are conceptions; we could equally write..........

#H_2Orightleftharpoons H^+ +HO^-#

So what is the #"acidium ion"#? As far as anyone knows it is a cluster of 3-4 water molecules with an EXTRA proton tacked on to give #H_7O_3^+# or #H_9O_4^+#. We write #H^+# or #H_3O^+# as a convenient shorthand.