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: Gas chromatography separates based on
A) Solubility
B) Boiling point
C) Vapor pressure
D) Density
✅ Correct Answer: B
Explanation: Volatile compounds elute by boiling characteristics.
Q: Heat transfer by conduction is most efficient in
A) Vacuum
B) Gases
C) Solids
D) Liquids
✅ Correct Answer: C
Explanation: Because solids have closely packed molecules that transfer energy more effectively.
Q: Steam reforming primarily converts hydrocarbons into
A) Methanol
B) Hydrogen
C) Ethanol
D) Ammonia
✅ Correct Answer: B
Explanation: Steam reforming uses heat and steam to produce hydrogen from hydrocarbons like methane.
Q: Ideal gas law becomes inaccurate at
A) High pressure
B) Low temperature
C) Low pressure
D) High temperature
✅ Correct Answer: A
Explanation: At high pressures, gas molecules interact more, violating the ideal gas assumptions.
Q: The equipment used to dry heat-sensitive materials
A) Tray dryer
B) Rotary dryer
C) Freeze dryer
D) Spray dryer
✅ Correct Answer: C
Explanation: Freeze drying preserves material integrity by sublimating moisture at low temperatures.
Q: Zinc is commonly extracted from
A) Sphalerite
B) Chalcopyrite
C) Hematite
D) Bauxite
✅ Correct Answer: A
Explanation: Sphalerite (ZnS) is the main ore of zinc.
Q: The function of Raschig rings in a tower
A) Pressure reduction
B) Heat transfer
C) Absorption
D) Increase surface area
✅ Correct Answer: D
Explanation: Raschig rings provide more contact area for gas-liquid interactions in packed columns.
Q: Nusselt number relates to
A) Mass transfer
B) Momentum transfer
C) Heat flux
D) Convective heat transfer
✅ Correct Answer: D
Explanation: The Nusselt number measures the enhancement of heat transfer through convection.
Q: The key controlling parameter in distillation
A) Temperature gradient
B) Reflux ratio
C) Pressure
D) Tray diameter
✅ Correct Answer: B
Explanation: Reflux ratio directly affects purity and separation efficiency in distillation.
Q: Fouling in heat exchangers causes
A) Pressure drop
B) Enhanced flow
C) Increased efficiency
D) Insulation failure
✅ Correct Answer: A
Explanation: Fouling reduces heat transfer efficiency and causes pressure losses.