* pH and pOH: pH and pOH are measures of acidity and alkalinity, respectively. They are related to the concentrations of hydronium ions (H3O+) and hydroxide ions (OH-) by the following equations:
* pH = -log[H3O+]
* pOH = -log[OH-]
* Kw (The Ion Product Constant): In any aqueous solution, the product of the concentrations of H3O+ and OH- is a constant value known as Kw. At 25°C, Kw = 1.0 x 10^-14.
* Kw = [H3O+][OH-]
* Neutral Solutions: When the concentrations of H3O+ and OH- are equal, this means:
* [H3O+] = [OH-]
* Substituting into the Kw equation: Kw = [H3O+]² = [OH-]²
* Therefore, [H3O+] = [OH-] = √Kw = 1.0 x 10^-7 M
* pH = 7: Since [H3O+] = 1.0 x 10^-7 M, the pH of a neutral solution is:
* pH = -log(1.0 x 10^-7) = 7
In summary: When the concentrations of H3O+ and OH- are equal, the solution is neutral with a pH of 7.
