While the pH scale is typically presented as ranging from 0 to 14, it is theoretically possible for pH values to be less than zero. This occurs with extremely concentrated strong acids, where the concentration of hydrogen ions ([H+]) is significantly higher than 1 mol/L.
The pH scale is logarithmic, meaning that each unit change in pH represents a tenfold change in hydrogen ion concentration. Therefore, a pH of 0 corresponds to a hydrogen ion concentration of 1 mol/L. However, solutions with even higher hydrogen ion concentrations will have negative pH values.
For example, a solution with a hydrogen ion concentration of 10 mol/L would have a pH of -1.
It is important to note that measuring pH values below zero requires specialized equipment and techniques due to the extreme acidity of such solutions.
Examples of solutions with pH values less than zero:
- Concentrated sulfuric acid (H2SO4)
- Concentrated hydrochloric acid (HCl)
Practical implications:
- The pH scale is a useful tool for measuring the acidity or alkalinity of solutions, but it is important to remember that it is a logarithmic scale.
- Solutions with pH values less than zero are extremely corrosive and should be handled with extreme caution.
