UPSC Prelims 2006 Q6: Science & Technology – Health & Diseases
Consider the following statements:
1. Caffeine, a constituent of tea and coffee, is a diuretic.
2. Citric acid is used in soft drinks.
3. Ascorbic acid is essential for the formation of bones and teeth.
4. Citric acid is a good substitution for ascorbic acid in our nutrition.
Which of the statements given above are correct?
- (a) 1 and 2 only
- (b) 1, 2 and 3 only
- (c) 3 and 4 only
- (d) 1, 2, 3 and 4
Answer: (b) 1, 2 and 3 only
Explanation
Caffeine, citric acid and ascorbic acid
| Statement | Verdict | Reason |
|---|---|---|
| 1. Caffeine is a diuretic | True | It increases urine output |
| 2. Citric acid is used in soft drinks | True | Acts as acidulant, flavour and preservative |
| 3. Ascorbic acid is essential for bones and teeth | True | Vitamin C is needed for collagen formation in bone matrix and dentin |
| 4. Citric acid can substitute ascorbic acid | False | Citric acid is not a vitamin and has no vitamin C activity |
So statements 1, 2 and 3 are correct.
Answer: (b) 1, 2 and 3 only.
Why each option is right or wrong
- (a) Incorrect. 1 and 2 only leaves out statement 3, which is true because ascorbic acid builds collagen for bones and teeth.
- (b) CORRECT. Statements 1, 2 and 3 are true; statement 4 is false.
- (c) Incorrect. 3 and 4 only wrongly accepts statement 4 and drops statements 1 and 2.
- (d) Incorrect. All four wrongly accepts statement 4; citric acid cannot replace vitamin C.
Key point
Caffeine is a diuretic, citric acid is a soft-drink additive and vitamin C aids bone and tooth formation, but citric acid cannot replace ascorbic acid.
Remember
Citric acid cannot substitute vitamin C (ascorbic acid).
Common mistakes
- Treating citric acid as another name for vitamin C because both occur in citrus fruits.
- Forgetting that vitamin C is needed for collagen, hence bones and teeth.
- Missing that caffeine acts as a mild diuretic.
Exam tip
Citric acid is a food acid; ascorbic acid is vitamin C. Similar sources, different functions.
Sources
- NCERT Class XII Chemistry — Chemistry in Everyday Life
- NCERT Class XII Chemistry — Biomolecules (vitamins)