What would a 0.12M solution of an acid that ionizes only slightly in solution be termed?

1 Answer
Jun 7, 2017

Regardless of its concentration, it is called a weak electrolyte. Weak electrolytes dissociate slightly in solution, i.e. they form few ions in solution for a given sample of solute.

(We thus expect the conductivity of this solution to be low.)

Since it is an acid, it is also a weak acid.

We thus describe this small dissociation, or ionization, using the acid dissociation constant,

#K_a = (["A"^(-)]["H"^(+)])/(["HA"])#

for the reaction

#"HA"(aq) rightleftharpoons "A"^(-)(aq) + "H"^(+)(aq)#,

and for weak acids, #K_a# tends to be smaller than #1#. For example, acetic acid has #K_a = 1.76 xx 10^(-5)#.