Why pH scale is from 0-14 .can it increases from 14 if not then why?

The pH scale is from 0-14 because it represents the range of hydrogen ion concentrations that can be measured in aqueous solutions. The pH scale was designed to be logarithmic, which means that each unit on the scale represents a tenfold difference in hydrogen ion concentration.

A solution with a pH of 0 has the highest concentration of hydrogen ions, while a solution with a pH of 14 has the lowest concentration of hydrogen ions. A solution with a pH of 7 is considered neutral, meaning it has an equal concentration of hydrogen ions and hydroxide ions.

 The reason the pH scale does not go beyond 14 is because a solution with a pH of 14 already has a very low concentration of hydrogen ions. If the concentration of hydrogen ions were to decrease any further, the solution would no longer be aqueous and would instead be a non-aqueous solution or a pure substance.

However, there are some non-aqueous solutions and pure substances that can be characterized by acidity or basicity. In these cases, other scales such as the Hammett acidity function or the pKa scale may be used to measure acidity or basicity. These scales may have different ranges and units than the pH scale.