Explain why the pH scale stretches between the numbers 0 to 14.
It's a logarithmic scale.
http://www.sciencebuddies.org/science-fair-projects/project_ideas/Chem_AcidsBasespHScale.shtml
The pH scale is a measure of how acidic or basic a substance is. It ranges from 0 to 14 because it is based on the concentration of hydrogen ions (H+) in a solution.
To understand why the pH scale stretches between 0 to 14, we need to look at the definition of pH. pH is a mathematical measure of the acidity or basicity of a solution. It is defined as the negative logarithm (base 10) of the concentration of hydrogen ions in a solution.
At the lowest end of the pH scale, a pH of 0 indicates a high concentration of hydrogen ions, making the solution highly acidic. As the concentration of hydrogen ions increases, the pH decreases.
On the other hand, at the highest end of the pH scale, a pH of 14 indicates a very low concentration of hydrogen ions, making the solution highly basic or alkaline. As the concentration of hydrogen ions decreases, the pH value increases.
At a neutral pH of 7, the concentration of hydrogen ions and hydroxide ions (OH-) in a solution are equal, indicating a balanced or neutral solution. This is the pH of pure water, which is neither acidic nor basic.
The range of 0 to 14 on the pH scale covers a wide range of possible hydrogen ion concentrations, from extremely acidic to extremely basic. It is a logarithmic scale, which means that each number on the scale represents a tenfold difference in hydrogen ion concentration. For example, a solution with a pH of 3 is ten times more acidic than a solution with a pH of 4.
In summary, the pH scale stretches from 0 to 14 to cover the range of hydrogen ion concentrations in a solution, with 0 being extremely acidic, 7 being neutral, and 14 being extremely basic. The scale provides a simple and standardized way to measure and compare the acidity or basicity of different substances.