Acid Strength Acid Strength And Molecular Structure Acid Strength and Percent Ionization Do not confuse the term acid strength with pH. The strength of an acid has to do with the percentage of the initial number of acid molecules that are ionized. On the other hand, there are certain acids that will not ionize very easily when added to water. These acids will only give up there protons to water with difficulty.
Weak acids can exhibit low pH readings just as strong acids.
Acid strength of weak acids has more to do with the value of the ionization constant of the acid. The percentage of ioninzation will therefore be larger. Strong acids have K a 's that approach infinity in value. Relative Strengths of Acids and Bases To understand why the K a approaches infinity in value, let's compare the acid strengths of the components in the solution capable of acting as an acid. Let's assume that we could reverse this process and proceed to the left.