Question

pH has great importance in our daily life. Explain by giving three examples.

Answer 1

pH:

1. It is the measure of acidity or basicity of a solution.
2. The pH ranges from 0 to 14.
3. For acid solutions pH is below 7.
4. For basic solutions pH is above 7.
5. For neutral solutions pH is equal to 7.

Importance of pH in our daily life:

pH is useful in comparing the acidic and basic strength of solutions. pH is useful in a number of ways in daily life which will be discussed below.

pH of our digestive system:

1. Hydrochloric acid is produced in our stomach and helps in digestion.
2. The excess of acid may lead to indigestion, pain and irritation. So the pH of the digestive in the stomach decreases.
3. The excessive acid in the stomach is a by antacids.
4. Antacids are a group of compounds which are basic in nature.
5. The common antacid used is Milk of Magnesia which is insoluble Magnesium hydroxide.
6. Aluminium hydroxide is also used as an antacid.
7. Antacid neutralises the H⁺ ions released by hydrochloric acid and brings the pH of the system to normal.

pH change leads to tooth decay:

1. The white enamel coating of our teeth is insoluble calcium phosphate and it is hard. It is not affected by water.
2. When the pH of the teeth falls below 5.5, the enamel gets corroded. so the water directly goes to the root and thus tooth decay occurs.
3. The bacterias present in the mouth breaks the sugar that we eat into acid such as lactic acid.
4. This acid formation leads to a decrease in pH and thus the enamel coating breaks.
5. The toothpaste that we use contains some basic ingredients that help neutralise the effect of acids and increase the pH.

Soil pH and plant growth:

1. The growth of plants depends on the pH of the soil.
2. Different plants require different pH for their growth.
3. The soils with high peat content or iron minerals or with rotting vegetation tend to become acidic.
4. The pH of the soil can be as low as 4.
5. The acidic effect of the soil is neutralised by liming the soil which is caused by adding calcium hydroxide or calcium oxide or powdered chalk for neutralising the effect as these all are bases.
6. On the other hand these alkaline substances can increase the basicity of soil. thus the soil can reach up to 8.3pH and it is harmful to plant growth.
7. The basicity can be reduced by adding some organic decaying matter which is acidic like compost or manure.

Hence, the pH plays an important role in our daily life.