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 166 of 350
- A. Crystallise faster
- B. Resist greater tensile stress at room temperature
- C. Have higher melting temperature
- D. Are better conductor of electricity at higher temperature
Explanation: Ceramics are held together by strong ionic or covalent bonds, giving them generally higher melting temperatures than metallic materials.
Correct answer: Have higher melting temperature- A. Heavy
- B. Structural
- C. Process
- D. Electronic
Explanation: Laser welding produces a narrow, precise weld with a small heat-affected zone, making it especially useful for delicate electronic…
Correct answer: Electronic- A. Microwaves
- B. X-rays
- C. Gamma rays
- D. Gas welding
Explanation: Microwave welding is suitable for joining very thin foils because it can provide localized heating with limited distortion of the thin…
Correct answer: Microwaves- A. 0.03
- B. 0.3
- C. 0.8
- D. 1.5
Explanation: A cupola typically consumes about 0.3 ton of coke per ton of cast iron produced, although the exact amount varies with furnace operation…
Correct answer: 0.33305. Satellites burn off during re-entry to earth's atmosphere, because of the ____________________?
- A. Combustion with air
- B. Gravitational pull by earth
- C. Loss in weight of the satellite
- D. Friction with earth's atmosphere
Explanation: During atmospheric re-entry, the satellite encounters air at very high relative velocity, producing intense aerodynamic heating through…
Correct answer: Friction with earth's atmosphere3306. With increase in temperature, the electrical conductivity of semiconductors_____________________?
- A. Increases
- B. Decreases
- C. Remain constant
- D. Either A. or B. depends on the type of semi-conductor
Explanation: Heating a semiconductor generates additional electron-hole charge carriers, so its electrical conductivity increases with temperature.
Correct answer: Increases- A. Period increases
- B. Both 'B' & 'C'
- C. Group increases
- D. Period decreases
Explanation: Across a period, increasing nuclear charge pulls the electron cloud inward, so atomic size decreases.
Correct answer: Both 'B' & 'C'- A. 768
- B. 908
- C. 1400
- D. 1539
Explanation: The Curie point of iron is approximately 768°C, above which ferromagnetic iron becomes paramagnetic.
Correct answer: 768- A. Increasing the concentration of N2
- B. Decrease in pressure
- C. Increase in pressure
- D. Decrease in temperature
Explanation: Formation of NO is endothermic, so the reverse decomposition is exothermic and is favoured by lowering the temperature.
Correct answer: Decrease in temperature- A. Both low temperature and high pressure
- B. Low pressure
- C. Low temperature only
- D. High temperature
Explanation: Ammonia formation is exothermic, so lowering temperature favours it, while the reaction changes four gas moles into two and therefore high…
Correct answer: Both low temperature and high pressure3311. The unit of equilibrium constant of a chemical reaction is the same as that of__________________?
- A. Molar concentration
- B. Temperature
- C. None of these
- D. Internal energy
Explanation: The units of an equilibrium constant depend on the reaction stoichiometry and the convention used for activities, so they are not…
Correct answer: None of these- A. Increase the partial pressure of H2
- B. Increase the partial pressure of I2
- C. Increase the total pressure and hence shift the equilibrium towards the right
- D. Not affect the equilibrium conditions
Explanation: For H + I e2 2HI, the change in gaseous moles is zero, so adding an inert gas cannot alter the equilibrium composition.
Correct answer: Not affect the equilibrium conditions- A. Increases, for an exothermic reaction
- B. Decreases, for an exothermic reaction
- C. Increases, for an endothermic reaction
- D. None of these
Explanation: For an exothermic reaction, heat behaves like a product, so raising temperature shifts equilibrium toward reactants and lowers the…
Correct answer: Increases, for an exothermic reaction- A. Zero
- B. Not possible to predict
- C. Very large compared to that for endothermic reaction
- D. Negative
Explanation: The sign or magnitude of activation energy cannot be determined merely from whether a reaction is exothermic or endothermic; it depends on…
Correct answer: Not possible to predict- A. The equilibrium constant of a reaction depends upon temperature only
- B. With increase in temperature, the equilibrium constant increases for an exothermic reaction
- C. The conversion for a gas phase reaction increases with increase in pressure, if there is a
- D. decrease in volume accompanying the reaction
Explanation: For an exothermic reaction, heat behaves like a product, so increasing temperature shifts equilibrium backward and decreases the…
Correct answer: With increase in temperature, the equilibrium constant increases for an exothermic reaction- A. Law of corresponding state
- B. Kopp's rule
- C. Le-Chatelier principle
- D. Arrhenius hypothesis
Explanation: Le Chatelier's principle predicts that an equilibrium responds to a change in temperature, pressure, or concentration by shifting in the…
Correct answer: Le-Chatelier principle- A. Law of mass action
- B. Henry's law
- C. Hess's law
- D. None of these
Explanation: The law of mass action expresses the equilibrium constant in terms of the activities or concentrations of reactants and products, each…
Correct answer: Law of mass action- A. Very high pressure is required resulting in costly pressure vessel
- B. Rate of reaction is very low
- C. Space velocity of gas is very low resulting in decreased conversion
- D. None of these
Explanation: Lowering temperature improves the equilibrium yield of ammonia, but it greatly reduces the reaction rate because N2 dissociation is…
Correct answer: Rate of reaction is very low- A. 1500-1700
- B. 300 - 450
- C. 700 - 1000
- D. 100-200
Explanation: Naphtha steam reforming is carried out at high temperature, commonly in the approximate range of 700 to 1000°C, to promote the strongly…
Correct answer: 700 - 1000- A. Nickel
- B. Pt-Rh
- C. Silica gel
- D. Co-Mo
Explanation: Cobalt-molybdenum catalysts, commonly supported on alumina, are used for hydrodesulphurisation of naphtha.
Correct answer: Co-Mo