A scale for measuring hydrogen particle concentration in a arrangement is called pH scale. (The ‘p’ in pH stands for ‘Potenz’. In German Dialect ‘Potenz’ is control). pH esteem of a solution is simply a number which shows the acidic or fundamental nature of a solution. The pH of impartial arrangements is 7. Values less than 7 on the pH scale represent an acidic arrangement.

As the pH esteem increments from 7 to 14, it represents a diminish in H3 O+ particle concentration or an increment in OH– ion concentration within the arrangement. pH esteem of a arrangement over ‘7’ represents a essential arrangement. The strength of acid or base depends on the concentraction of H3 O+ ions or OH– produced in solution. If we take hydrochloric acid and acetic acid of the same concentration then they produce different concentration of hydrogen ions.