1. Explain how the pH of the soil is affecting crop growth.

2. Suggest a suitable chemical that can be added to improve soil fertility.

3. Why is this chemical preferred over a strong base such as sodium hydroxide?

   
   

   1. Q2. A person suffering from indigestion consumes an antacid tablet.

      1. Why does indigestion occur in terms of acid concentration in the stomach?

      2. Explain how an antacid provides relief.

      3. Why are antacids generally weak bases and not strong bases?

      4. Name one commonly used antacid.

         Q3. A toothpaste manufacturer claims:

         “Our toothpaste helps prevent tooth decay by maintaining the correct pH in the mouth.”

         Using your knowledge of pH, answer:

         1. What causes the pH of the mouth to decrease after eating sugary food?

         2. Below which pH does tooth enamel start getting damaged?

         3. How does toothpaste help in preventing tooth decay?

         4. Explain why regular brushing is important from a chemical point of view.

Ans1- A soil pH of 4.8 is highly acidic. Most agricultural crops require a neutral pH range between 6.0 and 7.0 to grow successfully. This extreme acidity lowers crop yields by damaging the root system and restricting nutrient intake.

Ans2-The most effective chemical to fix a soil pH of 4.8 is Calcium Carbonate commonly known as agricultural limestone.

Ans3-Sodium hydroxide is not used to fix acidic soil because it is highly soluble in water and can be extremely toxic.While it is a strong base that can neutralize acid quickly, it causes severe damage to the soil structure and can gradually kill the crop.

Q-2

Ans-1 When the gastric glands of stomach produce excessive amount of Hydrochloric Acid from the purpose of digestion it leads to acidity often reffered as indigestion and slight to high burning inside the stomach due to its corrosive nature.

Ans-2 To get relief, we take antacids, which are mild chemical bases such as Magnesium Hydroxide also known as milk of magnesia .The antacid reacts with the excess hydrochloric acid in the stomach. This chemical reaction is called a neutralisation reaction. The base neutralises the excess acid to form salt and water, thereby reducing the acidity and providing immediate relief from pain.