Chemical Engineering MCQs
Chemical Engineering MCQs provide a strong foundation for those preparing for competitive exams and interviews in the chemical industry. The questions cover core topics including process calculations, heat transfer, mass transfer, chemical reaction engineering, plant design, safety, and environmental concerns. Whether you are a fresh graduate or preparing for job assessments through FPSC, PPSC, or NTS, this section helps reinforce key concepts and identify knowledge gaps. The MCQs reflect actual exam trends and are especially useful for test-based recruitment and academic success in the chemical engineering field.
Q: Minimum boiling azeotropes
A) Separate easily
B) Boil at high temp
C) Boil at constant temp
D) Are unstable
✅ Correct Answer: C
Explanation: Maintain fixed composition when boiling.
Q: Joule-Thomson effect occurs during
A) Combustion
B) Expansion
C) Cooling
D) Compression
✅ Correct Answer: B
Explanation: Cooling during expansion without heat exchange.
Q: Chemical potential relates to
A) Mass transfer
B) Phase equilibrium
C) Diffusion
D) Kinetics
✅ Correct Answer: B
Explanation: Governs component behavior across phases.
Q: Mass transfer in gases mainly by
A) Convection
B) Conduction
C) Diffusion
D) Radiation
✅ Correct Answer: C
Explanation: Molecules spread out via diffusion.
Q: Reverse osmosis is used for
A) Sterilization
B) Desalination
C) Filtration
D) Absorption
✅ Correct Answer: B
Explanation: Forces water through membranes to remove salt.
Q: Mean free path is important in
A) Thermodynamics
B) Surface tension
C) Mass transfer
D) Molecular diffusion
✅ Correct Answer: D
Explanation: Average distance between molecular collisions.
Q: Spray dryers convert
A) Gas to solid
B) Vapor to liquid
C) Liquid to powder
D) Powder to liquid
✅ Correct Answer: C
Explanation: Used for drying heat-sensitive materials.
Q: In distillation, higher reflux ratio leads to
A) Less purity
B) Higher separation
C) Shorter column
D) Lower efficiency
✅ Correct Answer: B
Explanation: Improves separation of components.
Q: Absorption accompanied by chemical reaction is called
A) Reactive absorption
B) Simple absorption
C) Dissolution
D) Chemisorption
✅ Correct Answer: D
Explanation: Chemical bonding involved in absorption.
Q: Critical point is when
A) Solid = Liquid
B) Vapor = Solid
C) Liquid = Vapor
D) No phase exists
✅ Correct Answer: C
Explanation: At this point, gas and liquid become indistinguishable.