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: Vapor pressure increases with
A) Decreasing temperature
B) Increasing temperature
C) Increasing altitude
D) Adding solids
✅ Correct Answer: B
Explanation: Temperature drives vapor pressure up.
Q: Main reason for using baffles in reactors
A) Prevent sedimentation
B) Increase cost
C) Reduce reaction
D) Improve mixing
✅ Correct Answer: D
Explanation: Ensures proper agitation.
Q: Residence time distribution is important for
A) Kinetic data
B) All of these
C) Ideal mixing assumption
D) Equipment sizing
✅ Correct Answer: B
Explanation: Affects reactor design and conversion.
Q: BOD removal in aeration tank involves
A) Adsorption
B) Precipitation
C) Sedimentation
D) Microbial degradation
✅ Correct Answer: D
Explanation: Bacteria break down organic matter.
Q: Solubility of gases in liquids decreases with
A) Agitation
B) Temperature
C) Pressure
D) Mixing
✅ Correct Answer: B
Explanation: Gases are less soluble at higher temperatures.
Q: Fluidized bed combustion enhances
A) Fuel consumption
B) Thermal insulation
C) Corrosion
D) Heat transfer
✅ Correct Answer: D
Explanation: Provides better combustion and heat exchange.
Q: Design pressure of a vessel depends on
A) Material
B) Fluid color
C) Max operating pressure
D) Thickness
✅ Correct Answer: C
Explanation: Safety requires overdesign beyond operating pressure.
Q: Plug flow reactors have
A) Ideal mixing
B) Dead zones
C) Uniform output
D) Back mixing
✅ Correct Answer: C
Explanation: Plug flow assumes no mixing in axial direction.
Q: Enthalpy is defined as
A) Internal energy + PV
B) Energy + flow work
C) Internal energy + pressure
D) Heat + temperature
✅ Correct Answer: A
Explanation: Thermodynamic property useful in flow systems.
Q: Most corrosion-resistant material below
A) Mild steel
B) Stainless steel
C) Copper
D) Aluminum
✅ Correct Answer: B
Explanation: Stainless steel offers excellent corrosion resistance.