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: Boiling point elevation is used in
A) Crystallization
B) Evaporation
C) Filtration
D) Reverse osmosis
✅ Correct Answer: B
Explanation: Evaporation benefits from boiling point elevation to separate liquids from solids.
Q: Slurry transport in pipelines requires
A) Peristaltic pumps
B) Gear pumps
C) Positive displacement pumps
D) Centrifugal pumps
✅ Correct Answer: D
Explanation: Centrifugal pumps are preferred for handling abrasive slurry materials.
Q: The main reason for catalyst deactivation
A) Acid-base reaction
B) Coking
C) Oxidation
D) Overheating
✅ Correct Answer: B
Explanation: Carbon deposition or coking blocks active sites on catalyst surfaces.
Q: Degree of freedom in a two-component system with one phase
A) 1
B) 0
C) 2
D) 3
✅ Correct Answer: C
Explanation: Gibbs phase rule: F = C - P + 2 → 2 - 1 + 2 = 3.
Q: Reynolds number is the ratio of
A) Inertial to viscous forces
B) Heat to mass transfer
C) Work to energy
D) Pressure to velocity
✅ Correct Answer: A
Explanation: It predicts flow regime based on the ratio of inertial to viscous forces.
Q: Laminar flow is usually assumed when Reynolds number is below
A) 1000
B) 3000
C) 2300
D) 2000
✅ Correct Answer: C
Explanation: For pipe flow, laminar conditions are defined for Re < 2300.
Q: The catalyst used in the Haber process
A) Vanadium pentoxide
B) Platinum
C) Iron
D) Nickel
✅ Correct Answer: C
Explanation: Finely divided iron is used in the Haber process to synthesize ammonia.
Q: The separation technique used for azeotropic mixtures
A) Flash distillation
B) Batch distillation
C) Extractive distillation
D) Simple distillation
✅ Correct Answer: C
Explanation: Extractive distillation uses an additional solvent to separate azeotropes.
Q: Chlor-alkali process primarily yields
A) NaCl and H₂O
B) NaOH and Cl₂
C) HCl and NaCl
D) H₂SO₄ and H₂
✅ Correct Answer: B
Explanation: This electrolysis of brine produces sodium hydroxide, chlorine gas, and hydrogen.