Free Chemical Reaction Engineering MCQs with Answers
395 Chemical Reaction Engineering MCQs from Chemical Engineering, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
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- A. Vanadium pentoxide
- B. No
- C. Alumina
- D. Nickel
Explanation: Industrial urea formation from ammonia and carbon dioxide proceeds through ammonium carbamate without an added catalyst.
Correct answer: No- A. Endothermic
- B. None of these
- C. Irreversible
- D. Exothermic
Explanation: The Haber reaction releases heat when nitrogen and hydrogen form ammonia, so it is exothermic.
Correct answer: Exothermic- A. Low pressure
- B. Atmospheric pressure; as the pressure has no effect on conversion
- C. Very high temperature
- D. High pressure
Explanation: The reaction changes four moles of reactant gas into two moles of product gas.
Correct answer: High pressure- A. Increases
- B. Decreases
- C. Remains unaltered
- D. Can either increase or decrease depends on biuret content
Explanation: Urea is formed by the dehydration of ammonium carbamate under high-pressure conditions, and increasing pressure favours the high-pressure…
Correct answer: Increases- A. Polythene
- B. Bakelite
- C. Poly vinyl chloride
- D. Polystyrene
Explanation: Bakelite is formed by condensation of phenol and formaldehyde, with water released as a by-product during network formation.
Correct answer: Bakelite- A. Shifting the equilibrium towards right
- B. Shifting the equilibrium towards left
- C. No change in equilibrium condition
- D. None of these
Explanation: The reactant side has two moles of gas and the product side also has two moles, so changing pressure does not favour either direction for…
Correct answer: No change in equilibrium condition- A. Temperature gradients are very high
- B. Segregation of the solids occurs
- C. Hot spots are formed
- D. Temperature is more or less uniform
Explanation: Intense mixing and circulation of particles and gas in a fluidized bed distribute heat efficiently, so the bed temperature is…
Correct answer: Temperature is more or less uniform- A. -20 to 25
- B. 250-280
- C. 100 to 150
- D. 50 to 75
Explanation: Caprolactam is polymerized industrially at about 250 to 280°C to form nylon-6.
Correct answer: 250-280- A. The monomers are unsaturated compounds
- B. No co-product is lost
- C. The monomers contain two functional groups
- D. Generally only one monomer is involved
Explanation: Condensation polymerization generally requires monomers with two or more reactive functional groups, allowing chains to grow while small…
Correct answer: The monomers contain two functional groups- A. Trichloroethylene
- B. Ethylene oxide
- C. Ethanol amine
- D. Vinyl chloride
Explanation: On thermal cracking, ethylene dichloride loses hydrogen chloride and forms vinyl chloride, the monomer used to manufacture PVC.
Correct answer: Vinyl chloride- A. The unit of space velocity is (time)-1
- B. The space velocity of 3 hr-1 means that three reactor volumes of feed at specified conditions
- C. are being fed into the reactor every hour
- D. conditions are being fed into the reactor
- E. The space velocity of 3 hr-1 means that one third reactor volume of feed at specified
- F. None of these
Explanation: Space velocity is volumetric feed rate divided by reactor volume, with units of inverse time.
Correct answer: The space velocity of 3 hr-1 means that one third reactor volume of feed at specified- A. Isothermal CSTR
- B. Non-isothermal CSTR
- C. Mixer
- D. None of these
Explanation: A non-isothermal CSTR is nonlinear because reaction rate depends exponentially on temperature through the Arrhenius relation, while…
Correct answer: Non-isothermal CSTR- A. 0
- B. 1
- C. 2
- D. 3
Explanation: For a rate law r = kCⁿ, tripling concentration changes the rate by 3ⁿ. Since the rate becomes 9 times greater, 3ⁿ = 9 = 3², so the…
Correct answer: 2- A. Ratio of liquid depth to tank diameter (i.e. the filling ratio) recommended for most purposes is 1
- B. Filling ratio for dispersing gas in a liquid is 2 for sufficiently long contact period
- C. Flat bottom and conical bottom vessels have low agitation efficiency for agitation of heavy solids in liquids
- D. Dished bottom vessel has very high power consumption
Explanation: A dished bottom generally improves liquid circulation and solid suspension, rather than requiring very high power consumption.
Correct answer: Dished bottom vessel has very high power consumption- A. Pot type reactor
- B. A vapor phase reactor
- C. A liquid phase reactor
- D. A liquid phase catalytic reactor
Explanation: A vapor-phase reactor generally has a smaller liquid inventory and avoids hazards associated with boiling, liquid leakage and catalyst…
Correct answer: A vapor phase reactor- A. 1
- B. < 1
- C. > 1
- D. Equal to the order of reaction
Explanation: For a positive-order reaction, the rate decreases as conversion increases, so a mixed reactor operates everywhere at the low exit…
Correct answer: > 1- A. Laminar flow
- B. Eddy diffusivity = 0
- C. Plug flow
- D. Complete back mixing
Explanation: The Peclet number compares convective transport with axial dispersion. Pe = 0 means dispersion dominates completely, corresponding to…
Correct answer: Complete back mixing- A. Aluminium chloride
- B. Alumina
- C. Nickel
- D. Phosphoric acid
Explanation: Aluminium chloride, usually with hydrogen chloride, is the classical catalyst system for paraffin isomerisation.
Correct answer: Aluminium chloride- A. 100
- B. 200-300
- C. 1000-10000
- D. 10
Explanation: Catalysts strongly accelerate the cracking of olefins by providing a lower-energy reaction pathway, making their cracking rate roughly…
Correct answer: 1000-10000- A. Enhances the desulphurisation process
- B. Both A. and B.
- C. Minimises coke formation
- D. Neither A. nor B.
Explanation: Hydrogen reacts with sulphur compounds over the hydrofining catalyst, increasing their conversion to removable hydrogen sulphide.
Correct answer: Both A. and B.