Question

Explain the importance of pH in daily life.

Hint:

Mnemonic: “{D-T-S-A-B}” → Digestion, Teeth, Soil, Aquatic life, Blood are main fields where pH is important.

Answer 1

Step 1: What is pH?
pH is a scale used to measure the concentration of hydrogen ions ($H^{+}$) in a solution. It indicates whether a substance is acidic, neutral, or basic. \[ pH = -\log[H^{+}] \] The pH scale ranges from 0 to 14.
$pH<7$: Acidic
$pH = 7$: Neutral
$pH>7$: Basic (alkaline)
Step 2: Importance of pH in Daily Life
In our Digestive System: Human stomach secretes hydrochloric acid ($HCl$) to help in digestion of food. The pH is around 1.5–3.5. Sometimes excess acid causes indigestion, which is treated using antacids like magnesium hydroxide that neutralise excess acidity.
In Tooth Decay: Tooth enamel is made of calcium phosphate. When bacteria in our mouth produce acids by degrading sugar, the pH of the mouth falls below 5.5. This corrodes the enamel and causes tooth decay. Using toothpaste (basic in nature) helps neutralise the acids.
In Soil for Plants: Plants require soil with proper pH for healthy growth. Some crops grow better in slightly acidic soil (pH 6–6.5), while others need slightly alkaline conditions. Farmers use lime ($CaCO_{3}$) to neutralise acidic soil.
In Aquatic Life: Aquatic organisms can survive only within a narrow pH range. Acid rain lowers the pH of rivers and lakes, making the water unsuitable for aquatic life. Hence monitoring pH of water is very important.
In Everyday Products:
Shampoos, soaps, and detergents are manufactured with balanced pH so that they do not harm skin or hair.
Blood in humans has a pH range of about 7.35–7.45, and even small changes can be life-threatening.
Final Answer:
The concept of pH plays a vital role in digestion, tooth health, agriculture, aquatic life, and even in the maintenance of human blood. Proper control of pH is essential for sustaining life and the environment.