What is pH?
pH is an abbreviation for “power of hydrogen“
The hydrogen ion concentration in pure water around room temperature is about 1.0 × 10-7 M. A pH of 7 is considered “neutral“, and the concentration of hydrogen ions is exactly equal to the concentration of hydroxide (OH–) ions from dissociation of the water.
Increasing the concentration of hydrogen ions above 1.0 × 10-7 M produces a solution with a pH of less than 7, and the solution is considered “acidic“.
Decreasing the concentration below 1.0 × 10-7 M produces a solution with a pH above 7, and the solution is considered “alkaline” or “basic“.
Solution of pH 1 is said to be 10 times as acidic as a solution of pH 2, because the hydrogen ion concentration at pH 1 is ten times the hydrogen ion concentration at pH 2.
