About this previous year paper
Subject: Chemical Engineering Thermodynamics – I (CH402)
Time: 3 Hours
Maximum Marks: 100
Section A – Short Questions (10 × 2 = 20 Marks)
This section focuses on definitions, basic principles, and conceptual understanding.
Topics include:
Second law of thermodynamics Volume expansivity
Heat engine concept Limitations of the first law of thermodynamics
Expression for gas expansion COP (Coefficient of Performance)
Joule–Thomson Coefficient Third Law of Thermodynamics
Thermodynamic property Closed system (with examples)
Section B – Descriptive / Problem-Based Questions (5 × 10 = 50 Marks)
Longer conceptual and numerical questions covering applied thermodynamics.
Key problems include:
Adiabatic compression of CO₂ — find Q, ΔU, and W for each step
Explanation of the critical point and P–V diagram
Derivation showing fugacity for a real gas obeying p(v−B)=RTp(v-B) = RTp(v−B)=RT
Derivation of the fundamental property relation and four Maxwell’s relations
Calculation of least rate of heat rejection for a heat engine between two reservoirs
Relation for entropy change during adiabatic mixing
Problem on entropy change when a hot steel casting is quenched in oil
Problem involving reversible expansion of a perfect gas with entropy change calculations
Section C – Long Analytical / Derivation Questions (2 × 15 = 30 Marks)
Conceptually deeper questions requiring derivations or detailed reasoning.
Questions include:
Turbine Problem – Calculate power output using given steam flow conditions (enthalpy, velocity, elevation, and heat loss data).
P–V Diagram Explanation – Discuss and derive work for isothermal and adiabatic processes.
Gibbs–Duhem Equation – Explain what it relates and derive its various forms.
Major Topics Covered
Laws of Thermodynamics
Energy equations for steady-flow systems
Entropy, fugacity, and equilibrium relations
Isothermal & adiabatic work
Maxwell’s relations
Gibbs–Duhem equation
Heat engines and efficiency concepts
Thermodynamic property relations