Potential of Hydrogen (PH) Scale

What is the full form of pH?

The full form of pH is Potential of Hydrogen. pH is known as the negative logarithm of H+ ion concentration. Hence the meaning of the name pH is explained as the strength of hydrogen. pH describes the concentration of the hydrogen ions in a solution and it is the indicator of acidity or basicity of the solution. The pH value on a pH-scale varies from 0 to 14.

The concentration of hydronium ion is conveniently expressed on a logarithmic scale. This scale is known as the pH scale. pH of acids and bases is defined as the negative logarithm (with base 10) of activity of hydrogen ion (H+).

pH of Acid And Base

The pH of the solution has a range from 0 to 14.

• Solutions with a pH value varying from 0 to 7 on the pH scale are called acidic solutions.
• Solution with a pH value ranging from 7 to 14 is known as basic solutions.
• On a pH scale, solutions with a potential of hydrogen value equal to 7 are known as neutral solutions.

Solutions with a pH-value of 0 are considered to be extremely acidic. Additionally, the acidity decreases as the pH value increase from 0 to 7 while solutions with a pH value equal to 14 are known to be strongly alkaline solutions. The acid and base intensity depends on the number of H⁺ and OH^– ions produced. Acids furnishing more H+ ions are known to be strong acids, and vice versa.

Importance of pH

• A living organism can withstand only a limited range of pH changes, and any more pH adjustments will make life difficult. For example: in the case of acid rain, the pH of the water is less than 7. It increases the pH of river water as it flows into a river which hinders the survival of marine life.
• The human stomach contains hydrochloric acid, which helps the digestion of the food. Because the stomach releases so much HCl we feel a lot of pain and discomfort during indigestion. It would be minimised by using antiacids.
• often the bacteria present in our mouth lower the pH of our mouth by generating acids by food particle degradation. Therefore, by maintaining the pH, we are told to clean our mouths with toothpaste that are basic to prevent their decay.
• In the case of bee-sting, we feel a lot of pain when the bee injects the methanoic acid through its sting. Therefore, we are usually recommended to apply baking soda or other mild bases to the surface because it helps to maintain the surface pH.