Class 10 Science Solutions English Medium

Importance of pH in daily life:

(i) Blood and our body: Our body functions between pH range of 7.0 to 7.8. Living beings can survive only in a narrow pH range. When the pH of rain water falls below 5.6, it is called acid rain.

Disadvantages of Acid Rain: When acid rain water flows into the river, the pH of the river water decreases. The survival of aquatic organisms becomes difficult in such a river.

(ii) Acidity of the soil: Sometimes due to low pH value of soil due to some reasons or due to acid rain, this land does not give good yield, because plants need a specific pH range for good yield. Due to the increase of acidic properties in the soil, the plants are harmed, due to which the crop is not good.

Remedy by correcting the pH range of the soil: To eliminate the acidity of the soil, chalk powder or lime is added to the soil so that by eliminating its acidity, the nature of the soil becomes alkaline.

(iii) Digestion of food in acidic medium: pH is also important from the hydrochloric acid (HCl) produced by our stomach. It also aids in the digestion of food at a specific pH without harming the stomach. Normally the pH range of our stomach works between about 1.5 - 3.5. In these also the following two situations occur.

(a) Hypoacidity: Some people have very little HCl secretion due to which their food is not digested or less digested. Such a condition is called low-acidity (dyspepsia). Such a person has to take acidic substances such as lemon or vinegar with his food, or have to take medicines that produce digestive juices.

(b) Hyperacidity: In the case of excessive acid production in the stomach, the person experiences pain and burning in the abdomen. An antacid has to be taken to relieve this pain or burning.

Antacid (Anti-acid medicine): Antacids are weak bases that reduce the effect of acid. For example, weak bases like milk of magnesia (magnesium hydroxide), aluminum hydroxide and sodium hydroxide are included in the ingredient of antacids. They neutralize the acidic effect.

(iv) Tooth-caries/tooth-decay : Normally the pH of the mouth remains 5.5. If its value falls below 5.5, then tooth decay begins. Tooth enamel is made up of calcium phosphate, which is the hardest substance in the body. It protects the teeth from the outside. When the pH of the mouth falls below 5.5, it slowly corrodes.

The reason for the low pH of the mouth: When we eat food or any sweet thing, after the meal, residual sugar and food substances remain in the mouth, on which the bacteria present in the mouth degrade it and produce acid from it. This acid destroys the enamel which is the main cause of tooth decay.

Protection from Tooth-Decay: It can be prevented by cleaning the mouth after meals. alkaline for mouth cleaning
The excess amount of acid can be neutralized by using toothpaste.
As a result of which dental caries can be prevented.