Strong acid





A strong acid is an acidic compound which ionizes completely or almost
completely in aqueous solution.

pH is the measure of acidity/base strength. It is defined well for aqueous
solutions as the -log10(M[H+]) - the negative of the log (base 10) of the
concentration of Hydrogen (or more accurately hydronium, H3O+) ions in
soultion. Neutral pure water at STP has an equilibrium concentration of 1
hydronium ion per 10,000,000 water molecules (M = 10 ^-7 ) and thus has a pH of 7.

Acidic materials have a pH lower than this and bases have a pH higher than this.

The corresponing basic equivalents are the strong bases.

Examples of strong acids:

   * Hydrochloric acid
   * Nitric acid
   * Sulphuric acid
   * Hydrobromic acid
   * Hydroiodic acid
   * Trichloro acetic acid
   * Perchloric acid

Differentiating between the strength of the strong acids in aqueous
solutions is impossible, because the concentration of hydrogen ions is
always equal to the concentration of the acid. Only through replacing water
with concentrated Acetic acid as a diluent one can observe and measure
diference in the tendency to dissociate the proton ion, among the strong
acids.

(The analogical way to differentiate between strength of the strong bases is
to use liquid ammonia as a diluent, instead of water).