Indian Forest Service (Mains), Chemistry optional · 2023 · Paper I
Q3(d). Pressure as a state function
Question
Show that the pressure of a gas obeying (P + a/Vm²)Vm = RT is a state function.
Model answer
The free solution for 2023 answers questions 1, 2, 4, 5 and 6, the ones picked in its time plan. Question 3 is answered in full in the IFoS Chemistry Paper I, 2021 to 2025 book, with every part of every paper.
Part of VKC Basic
Read the key points and the full model answer with VKC Basic
VKC Basic (₹999 for 6 months) opens every solved answer, the notes, the handbook and the daily answer archive. Every Mains test series includes it.
Printed copy and Kindle
UPSC Indian Forest Service (Main) Chemistry Paper I: Model Answers 2021 to 2025
- All eight questions of each paper, with the question printed above its answer
- Physical chemistry numericals worked with units; inorganic structures drawn
- Topic-wise weightage and a topic-wise index
Coversstate functionexact differentialEuler reciprocityvan der Waals type gaspressure
All parts of Question 3
- 3(a) Ionic distances and radius-ratio predictions10 marks
- 3(b) Avogadro constant from diffraction10 marks
- 3(c) Ideal and van der Waals pressures10 marks
- 3(d) Pressure as a state function10 marks