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: Distillation separates components based on differences in
A) Viscosity
B) Density
C) Boiling point
D) Molecular weight
✅ Correct Answer: C
Explanation: Key principle of distillation.
Q: Heat transfer primarily occurs through
A) All of the above
B) Radiation
C) Convection
D) Diffusion
✅ Correct Answer: A
Explanation: All modes contribute depending on conditions.
Q: Unit of dynamic viscosity in SI system
A) Poise
B) kg/m²
C) Pascal-second
D) N·m/s
✅ Correct Answer: C
Explanation: Correct SI unit for dynamic viscosity.
Q: Process used to convert hydrocarbons into aromatics
A) Cracking
B) Polymerization
C) Alkylation
D) Reforming
✅ Correct Answer: D
Explanation: Reforming increases aromatic content.
Q: Main purpose of a scrubber in a chemical plant
A) Removing particulates
B) Absorbing gases
C) Cooling gases
D) Neutralizing acids
✅ Correct Answer: B
Explanation: Scrubbers absorb harmful gases.
Q: Reynolds number helps to determine
A) Fluid velocity
B) Flow regime
C) Heat transfer rate
D) Pressure loss
✅ Correct Answer: B
Explanation: Indicates laminar or turbulent flow.
Q: Flash point is the temperature at which
A) Liquid freezes
B) Vapor ignites briefly
C) Liquid boils
D) Auto-ignition happens
✅ Correct Answer: B
Explanation: Flash point is crucial for safety.
Q: Centrifugal pumps are typically used for
A) High pressure
B) High viscosity
C) Low flow
D) Low viscosity
✅ Correct Answer: D
Explanation: Suitable for low-viscosity fluids.
Q: Hydraulic diameter is relevant in
A) Compressors
B) Open channels
C) Heat exchangers
D) Packed towers
✅ Correct Answer: C
Explanation: Used in non-circular duct flow calculations.
Q: Most common refrigerant in air-conditioning systems
A) Helium
B) Freon
C) Ammonia
D) CO₂
✅ Correct Answer: B
Explanation: Freon (CFCs) is widely used.