What is pH? Definition, pH Scale, Importance, and Everyday Use!

What is pH?

pH is the measure of H plus ions present in a solution indicating the acidic or basic strength of the solution. The pH of a neutral solution is 7. Values less than 7 on the scale represent an acidic solution, whereas, with the increase in the values from 7 to 14 on the scale, the basic strength of the solution increases. It is used to measure the relative amount of free hydrogen and hydroxyl ions in water.

pH is an abbreviation used for the Potential of Hydrogen. It is the measure of the alkalinity and acidity of a solution on a logarithmic scale. The term “pH” came from the German word ‘Potenz’, meaning power. The power is combined with Hydrogen.

The pH Scale

It is the measurement that is used to rank the given solution based on its acidity or alkalinity. The scale has values ranging from 1 to 14, 7 being the idle and neutral point. A value less than 7 indicates acidity and a value greater than 7 indicates basicity.

Importance of pH

  1. The pH of acid rain is 5.6. When the water from the acid rain flows into rivers it lowers the pH of the river water, which causes lots of damage to the aquatic life. Plants also require a specific range for healthy growth. You know that our stomach produces hydrochloric acid, which means its pH is less than 7.
  2. Our body works within the pH range of 7 to 7.8. Excess production of acid by the stomach causes pain and irritation. We usually take antacids to get rid of this pain. For example magnesium hydroxide i.e. Mg(OH)2 is an antacid that neutralizes the excess acid.
  3. Also after eating, the bacteria present in the mouth start producing acid due to the degradation of sugar and food particles leftover in the mouth. This reduces the pH of the mouth below 5.5 and the tooth enamel which is made up of calcium phosphate i.e. Ca3(PO4)2, which is the hardest substance in the body, starts decaying.
  4. Therefore it is advised to clean the mouth after eating food using some toothpaste. These toothpaste are generally basic in nature.
  5. When a bee stings someone it leaves some acid which results in pain and irritation. Using a mild base like baking soda can give some relief when applied over the affected area. Similarly, nettle leaves produce a stinging sensation when contacted because they inject formic acid i.e. HCOOH which results in burning pain. Rubbing some leaves of the dock plant over the affected area provides relief to the irritation.

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