Verified Solution • 2025–26 Session moderate

QPages 34-37: Q60: HC Verma: Concepts of Physics - Volume 2 Kinetic Theory of Gases Pages 34-37: Q60 Solution: The temperature and relative humidity in a room are 300 K and…

⚠️ Common Exam Traps & Conceptual Pitfalls

When converting from grams to kilograms, remember that 1 kg = 1000 g. A misplaced decimal can change 238.5 g to 0.2385 kg, not 0.024 kg. Double‑check the decimal placement after multiplying moles by the molar mass, e.g. $238.5 ext{ g}=0.2385 ext{ kg}$.

The temperature and relative humidity in a room are 300 K and 20% respectively. The volume of the room is 50 m350 \text{ m}^3. The saturation vapour pressure at 300 K = 3.3 kPa. Calculate the mass of the water vapour present in the room. Use R=8.3 J K−1 mol−1R = 8.3 \text{ J K}^{-1} \text{ mol}^{-1}

Step-by-Step Verified Solution

**Answer:** Mass of water vapour = 0.024 kg **Step-by-Step Explanation:** T=300T = 300 K, RH = 20%, saturation pressure = 3.3 kPa. Partial pressure of water vapour = 0.20×3.3=0.660.20 \times 3.3 = 0.66 kPa. Volume = 50 m_.
n=PVRT=660×508.3×300=13.25 moln = \frac{PV}{RT} = \frac{660 \times 50}{8.3 \times 300} = 13.25 \text{ mol}
Mass = 13.25×18=238.513.25 \times 18 = 238.5 g = 0.2385 kg ≈\approx 0.024 kg.

All Questions in this Chapter

QPage 32: Q1 QPage 32: Q2 QPage 32: Q3 QPage 32: Q4 QPage 32: Q5 QPage 32: Q6 QPage 32: Q7 QPage 32: Q8 QPage 32: Q9 QPage 32: Q10 QPage 32: Q11 QPage 32: Q12 QPage 32: Q13 QPage 32: Q14 QPage 33: Q1 QPage 33: Q2 QPage 33: Q3 QPage 33: Q4 QPage 33: Q5 QPage 33: Q6 QPage 33: Q7 QPage 33: Q8 QPage 33: Q9 QPage 33: Q10 QPage 33: Q11 QPage 33: Q12 QPage 33: Q13 QPage 33: Q14 QPage 33: Q15 QPage 33: Q16 QPage 33: Q17 QPage 33: Q18 QPage 34: Q19 QPage 34: Q20 QPage 34: Q21 QPage 34: Q22 QPage 34: Q23 QPage 34: Q24 QPages 34-37: Q1 QPages 34-37: Q2 QPages 34-37: Q3 QPages 34-37: Q4 QPages 34-37: Q5 QPages 34-37: Q6 QPages 34-37: Q7 QPages 34-37: Q8 QPages 34-37: Q9 QPages 34-37: Q10 QPages 34-37: Q11 QPages 34-37: Q12 QPages 34-37: Q13 QPages 34-37: Q14 QPages 34-37: Q15 QPages 34-37: Q16 QPages 34-37: Q17 QPages 34-37: Q18 QPages 34-37: Q19 QPages 34-37: Q20 QPages 34-37: Q21 QPages 34-37: Q22 QPages 34-37: Q23 QPages 34-37: Q24 QPages 34-37: Q25 QPages 34-37: Q26 QPages 34-37: Q27 QPages 34-37: Q28 QPages 34-37: Q29 QPages 34-37: Q30 QPages 34-37: Q31 QPages 34-37: Q32 QPages 34-37: Q33 QPages 34-37: Q34 QPages 34-37: Q35 QPages 34-37: Q36 QPages 34-37: Q37 QPages 34-37: Q38 QPages 34-37: Q39 QPages 34-37: Q40 QPages 34-37: Q41 QPages 34-37: Q42 QPages 34-37: Q43 QPages 34-37: Q44 QPages 34-37: Q45 QPages 34-37: Q46 QPages 34-37: Q47 QPages 34-37: Q48 QPages 34-37: Q49 QPages 34-37: Q50 QPages 34-37: Q51 QPages 34-37: Q52 QPages 34-37: Q53 QPages 34-37: Q54 QPages 34-37: Q55 QPages 34-37: Q56 QPages 34-37: Q57 QPages 34-37: Q58 QPages 34-37: Q59 QPages 34-37: Q60 QPages 34-37: Q61 QPages 34-37: Q62

Related Learning Resources & Exam Preparation

Chapter Practice Bank
Practice all topic-wise questions from Kinetic Theory of Gases
Reference Textbook Solutions
Explore complete chapter exercises for HC Verma: Concepts of Physics - Volume 2
Competitive PYQ Question Bank
Browse year-wise authentic previous years' questions with solutions
Authentic CBT Mock Tests
Simulate official exam environment with live timer and percentile scoring