Topic Acids
Asked 6 times across 3 UPSC exams over 42 years (1981–2023), peaking in 2023.
Key insights
- Most tested in CDS — 3 of 6 PYQs
- Most asked in 2023
- Recurs across 4 years (1981–2023)
How it travelled across exams
First appearance in each exam — the same idea, reframed.
CSE 1981 → CDS 2022 → NDA 2023
How the concept evolved
Rising — more than half its appearances (4 of 6) are since 2016.
Related concepts
Ideas UPSC tests alongside this one — keep exploring.
Sample questions
You've seen the pattern — here are a few of the actual PYQs.
CDS2023
Which one of the following statements regarding acids is not correct ?
- A Hydrochloric acid is present in the gastric juice secreted by the stomach.
- B Oxalic acid is found in tamarind paste.
- C Acetic acid is the main constituent of vinegar. ✓
- D Lemon and orange juices contain citric acid and ascorbic acid respectively.
✓ Correct answer: (C)
Science & Technology › Physics & Chemistry
CDS2023
Consider the following statements : While diluting concentrated nitric acid solution
- the concentration of [H3O+] ions/volume increases
- water must be added slowly to concentrated acid
- acid must be added slowly to water
Which of the statements given above is/are correct?
- A 1, 2 and 3
- B 1 and 2 only
- C 3 only ✓
- D 2 and 3 only
✓ Correct answer: (C)
Science & Technology › Physics & Chemistry
NDA2023
Which one of the following acid is used by goldsmith for cleaning of gold and silver articles ?
- A Sulphuric acid
- B Nitric acid ✓
- C Hydrochloric acid
- D Phosphoric acid
✓ Correct answer: (B)
Science & Technology › Physics & Chemistry
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