The pH of a solution with a 10^-8 mol/L hydrogen ion concentration is 8. This is because pH is based on a negative logarithmic scale. To convert between pH and hydrogen ion concentration, use this equation: pH = -log[H+], where [H+] is the concentration of hydrogen ions.
If pH decreases by 1, the hydrogen ion concentration is 10 times higher. Pure water at room temperature (about 25 C) has a pH of 7 and a hydrogen ion concentration of 10^-7 mol/L. Higher concentrations have a pH lower than 7 and are acidic. Lower concentrations correspond to higher pH and are basic.
