(a) Mention the pH range within which our body works. Explain how antacids give relief from acidity. Write the name of one such antacid.

(b) Fresh milk has a pH of 6. How does the pH change as it turns to curd? Explain your answer.

The human body functions optimally within a pH range of approximately 7.35 to 7.45, which is slightly alkaline. When acidity occurs, antacids can provide relief by neutralizing excess stomach acid. They typically contain compounds like magnesium hydroxide or calcium carbonate. One common antacid is Tums, which helps alleviate heartburn and indigestion.

Transformation of Milk to Curd

Fresh milk has a pH of around 6, which is considered neutral. As milk turns into curd, the pH decreases due to the production of lactic acid by bacteria during fermentation. This process lowers the pH, making curd slightly more acidic, typically around 4 to 5. This change not only affects the taste but also enhances the nutritional properties of the curd.