All Free Chemical Engineering MCQs with Answers
Every Chemical Engineering question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
6,983 questions · page 167 of 350
- A. 3.5 : 1
- B. 1.5 : 1
- C. 10 : 1
- D. 15 : 1
Explanation: A steam-to-carbon ratio of about 3.5:1 is commonly maintained in naphtha reforming to provide sufficient steam for conversion and to limit…
Correct answer: 3.5 : 1- A. High pressure, low reactants concentration, high temperature
- B. High pressure, high reactants concentration, low temperature
- C. High pressure, low reactants concentration, low temperature
- D. Low pressure, high reactants concentration, low temperature
Explanation: Ammonia synthesis is favoured by high pressure, high reactant concentration, and low temperature because the reaction forms fewer gas…
Correct answer: High pressure, high reactants concentration, low temperature- A. Al2O3
- B. Cr2O3
- C. K2O
- D. MnO
Explanation: Ammonia synthesis uses promoted iron, with K2O acting as an electronic promoter that improves catalyst performance.
Correct answer: K2O- A. Iron
- B. Nickel
- C. Vanadium pentoxide
- D. Alumina
Explanation: The Haber process uses finely divided iron as the main catalyst, usually promoted by oxides such as K2O, Al2O3 and CaO.
Correct answer: Iron- A. Endothermic
- B. Exothermic
- C. Autocatalytic
- D. None of these
Explanation: The Haber reaction, N2 + 3H2 ⇌ 2NH3, releases heat, so ammonia synthesis is exothermic.
Correct answer: Exothermic- A. Stabilisation
- B. Increasing the effectiveness
- C. All A, B & C
- D. Improving the strength & heat resistance
Explanation: Promoters improve several catalyst properties, including activity, stability, mechanical strength and resistance to heat.
Correct answer: All A, B & C- A. Autocatalytic
- B. Non-catalytic
- C. Exothermic
- D. Endothermic
Explanation: Steam reforming converts hydrocarbons with steam to synthesis gas and requires heat because the reforming reaction is strongly…
Correct answer: Endothermic- A. High cost of the high pressure vessel used for the reactor
- B. Comparatively higher pressure drop
- C. Higher pumping cost
- D. Chances of entrainment and disturbance of catalyst bed
Explanation: Ammonia synthesis occurs at very high pressure, so using several separate high-pressure reactor vessels would greatly increase equipment…
Correct answer: High cost of the high pressure vessel used for the reactor- 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 pressure3332. With increases in pressure, the conversion of Ammonium carbamate into urea___________________?
- 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