pH AND PLANTS
Plants require a specific pH of the soil for their proper growth. Plants cannot grow in too alkaline or too acidic soils. Therefore, for proper cultivation of crops it is important to have knowledge of the pH of the soil. If the soil is too acidic then its pH can be raised by adding lime (or slaked lime) which neutralizes the excess acid in the soil.
Similarly, if the soil is too alkaline then its pH can be lowered by adding gypsum or some other substance which can neutralize the excess alkali present in the soil.
pH IN OUR DIGESTIVE SYSTEM
The medium in our stomach is highly acidic and has pH around 1.2. Our stomach produces hydrochloric acid which helps in digestion of food. Sometimes the stomach produces too much hydrochloric acid. Excess acid in the stomach causes pain and irritation. It can also cause ulcers in the digestive system. The condition of excess acid in the stomach is referred to as hyperacidity. In order to treat hyperacidity, a patient is advised to take antacid tablets or antacid suspensions. The antacid preparations contain some mild base such as magnesium hydroxide as the active component which neutralizes the excess acid in the stomach and thus controls the pH in the stomach.
Mg(OH)2 + 2HCl à MgCl2 + 2H2O
pH AND TOOTH DECAY
Tooth enamel is the hardest substance in our body. It is made up of calcium tetraoxophosphate(V). It does not dissolve in water and mildly acidic solutions. However, it gets corroded slowly when pH in the mouth is below 5.5. When we eat food, some food particles remain sticking to the teeth. Bacteria present in the mouth produce acid by the degradation of sugar and food particles present in the mouth. This results in lowe1ing of pH in the mouth which promotes tooth decay. In order to prevent tooth decay avoid eating sugary foods. The mouth should be cleaned after eating food. Cleaning the teeth using toothpastes also helps in preventing tooth decay. Toothpastes are generally basic, therefore, they neutralize the excess acid in the mouth and thus prevent tooth decay.
The knowledge of pH also helps us in maintaining the proper acidity in many products such as shampoos, medicines, etc. pH of rain water can be used to detect the extent of certain pollutant gases in the atmosphere.