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Topic Thermochemistry
Asked 3 times across 2 UPSC exams over 31 years (1994–2025), peaking in 1994.
Key insights
- Most tested in CAPF — 2 of 3 PYQs
- Most asked in 1994
- Recurs across 3 years (1994–2025)
How it travelled across exams
First appearance in each exam — the same idea, reframed.
CSE 1994 → CAPF 2024
How the concept evolved
Rising — more than half its appearances (2 of 3) 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.
CAPF2025
Which one of the following is not an exothermic reaction?
- A Dissolution of calcium oxide in water
- B Decomposition of vegetable matter into compost
- C Decomposition of lead nitrate
- D Dilution of sodium hydroxide with water
Answer key not yet available (pending official release)
Science & Technology › Physics & Chemistry
CAPF2024
Which one among the following is an example of endothermic process?
- A Combustion of carbon
- B Mixing acid and alkali
- C Photosynthesis ✓
- D Respiration
✓ Correct answer: (C)
Science & Technology › Physics & Chemistry
CSE1994
One mole of hydrogen gas bums in excess of oxygen to give 290 kJ of heat. What is the amount of heat produced when 4g of hydrogen gas is burnt under the same conditions?
- A 145 Kj
- B 290 kJ
- C 580 kJ ✓
- D 1160 kJ
✓ Correct answer: (C)
Science & Technology › Physics & Chemistry
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