Question

Which of the following is NOT correctly matched?
1. Acid present in vinegar - Acetic acid
2. Compound present in bones- Calcium
3. Souring of milk - Nitric acid
4. Acid present in gastric juice - Hydrochloric acid

Answer 1

Correct Answer - Option 3 : Souring of milk - Nitric acid

Option 3 is incorrectly matched.

• The souring of Milk:
  • The sour odour and taste of sour milk and also of yoghurt is caused by the presence of lactic acid, not nitric acid.
  • Cause: Growth of lactic acid-producing organisms such as Lactococcus lactis, due to poor refrigeration, especially when temperatures exceed 70°F (21°C). Hence, option 3 is incorrectly matched.
• The compound present in bones:
  • ​About 99% of the calcium in the body is stored in the bones and teeth. It's the mineral that makes them hard and strong. Hence, option 2 is correctly matched.
  • The remaining 1% is needed for many activities that help keep the body functioning normally. 
• The acid present in vinegar:
  • Vinegar contains acetic acid. Hence, option 1 is correctly matched.
  • Acetic acid is also called ethanoic acid. 
  • Its chemical formula is CH₃COOH.
• The acid present in gastric juice:
  • Gastric juice is a unique combination of hydrochloric acid (HCl), lipase, and pepsin. Hence, option 4 is correctly matched.
  • Acidic gastric juice is found in all vertebrates, and its main function is to inactivate microorganisms.