Strong Acid and Base Solutions

Strong acids dissociate completely in water. For example, nitric acid dissociates completely into hydronium ions and nitrate ions. As the hydronium ions generated from the autoionization of water are negligible, the concentration of the hydronium ions in water is equal to the concentration of the strong acid.

The pH of these solutions can be determined using the initial concentration of the strong acid.

For example, in a 0.10 molar HCl solution, HCl will dissociate completely into the hydronium ions and chloride ions, and therefore the hydronium ion concentration of the solution will also be 0.10 molar. By taking the negative logarithm of this concentration, the pH of the solution is equal to one.

Conversely, the pH of a solution can be used to determine the hydronium ion concentration of a solution. For example, for a solution of pH 3.60, its hydronium ion concentration can be determined by solving the equation 3.60 is equal to the negative log of the hydronium ion concentration.

To solve for the concentration, multiply both sides by negative one, and then take the antilog of both sides. The hydronium ion concentration equals 2.5 times ten to the negative four molar.

Strong bases