Chemical Reaction Engineering Questions MCQs

chemical reaction engineering Questions

Total Questions : 446

Page 1 of 23 pages
Question 1. A batch reactor is characterised by
  1.    Constant residence time
  2.    Variation in extent of reaction and properties of the reaction mixture with time
  3.    Variation in reactor volume
  4.    Very low conversion
Answer: Option B
Question 2. A catalyst inhibitor
  1.    Lessens its selectivity
  2.    May be useful for suppressing undesirable side reactions
  3.    Is added in small quantity during the catalyst manufacture itself
  4.    All of the above
Answer: Option D
Question 3. Rate of a chemical reaction is not influenced by the
  1.    Catalyst
  2.    Temperature
  3.    Reactants concentration
  4.    Number of molecules of reactants taking part in a reaction
Answer: Option D
Question 4. In a continuous flow stirred tank reactor, the composition of the exit stream
  1.    Is same as that in the reactor
  2.    Is different than that in the reactor
  3.    Depends upon the flow rate of inlet stream
  4.    None of these
Answer: Option A
Question 5. Exothermic reactions are best carried out in
  1.    A CSTR
  2.    CSTR in series
  3.    A plug flow reactor followed by CSTR
  4.    CSTR followed by a plug flow reactor
Answer: Option D
Question 6. A chemical reaction occurs, when the energy of the reacting molecules is __________ the activation energy of reaction.
  1.    Less than
  2.    Equal to
  3.    More than
  4.    Equal to or more than
Answer: Option D
Question 7. For nearly isothermal operation involving large reaction time in a liquid-phase reaction, the most suitable reactor is a __________ reactor.
  1.    Stirred tank
  2.    Tubular flow
  3.    Batch
  4.    Fixed bed
Answer: Option A
Question 8. Slurry reactors are characterised by the
  1.    Lack of intraparticle diffusion resistance
  2.    Presence of two mobile phases
  3.    Both A and B
  4.    Neither A nor B
Answer: Option C
Question 9. Sulphuric acid is used as a catalyst in the
  1.    Hydrogenation of oils
  2.    Gas phase oxidation of SO₂ in chamber process
  3.    Alkylation of hydrocarbons
  4.    None of these
Answer: Option C
Question 10. The half life period of a first order reaction is
  1.    Always the same irrespective of the reaction
  2.    Dependent on initial concentration of the reactants
  3.    Proportional to the initial concentration of reactants
  4.    Half the specific rate constant
Answer: Option B
Question 11. In case of the irreversible unimolecular type, first order reaction, the fractional conversion at any time for constant volume system as compared to variable volume system is
  1.    More
  2.    Less
  3.    Same
  4.    Either A or B, depends on other factors
Answer: Option C
Question 12. The concentration of A in a first order reaction, A → B, decreases
  1.    Linearly with time
  2.    Exponentially with time
  3.    Very abruptly towards the end of the reaction
  4.    Logarithmically with time
Answer: Option B
Question 13. A second order reaction of the form A + B → C is called a pseudo-first order reaction, when
  1.    CA0 = CB0
  2.    CA0 > CB0
  3.    CB0 > CA0
  4.    CB0 ≥ CB0
Answer: Option D
Question 14. Pick out the correct statement.
  1.    A lower temperature favours the reaction of lower activation energy
  2.    The dispersion number for a reactor/vessel is uL/D
  3.    The rate controlling step in a reaction involving many steps is the fastetst step
  4.    Pore volume and porosity of a catalyst is measured by Brunaver-Emmet-Teller (BET) technique
Answer: Option A
Question 15. Arrhenious equation represents graphically the variation between the __________ and temperature.
  1.    Rate of reaction
  2.    Frequency factor
  3.    Rate constant
  4.    Activation energy
Answer: Option C
Question 16. Helium-mercury method is used for the measurement of the __________ of the catalyst.
  1.    Surface area
  2.    Porosity
  3.    Pore volume
  4.    Both B & C
Answer: Option D
Question 17. Sum of the powers of the concentration terms in the rate equation is called the __________ of the reaction.
  1.    Order
  2.    Overall order
  3.    Molecularity
  4.    None of these
Answer: Option B
Question 18. The value of 'n' for a chemical reaction A → B, whose reaction rate is → CAn, will be __________ if the rate of the reaction increases by a factor of 8, when the concentration of is doubled.
Answer: Option B
Question 19. The reaction A → B is conducted in an adiabatic plug flow reactor (PFR). Pure A at a concentration of 2 kmol/m³ is fed to the reactor at the rate of 0.01 m³ /s and at a temperature of 500 K. If the exit conversion is 20%, then the exit temperature (in k)is (Data: Heat of reaction at 298 K = - 50000 kJ/ kmole of A reacted Heat capacities CPA = CPB = 100kJ/kmole. K (may be assumed to be independent of temperature))
  1.    400
  2.    500
  3.    600
  4.    1000
Answer: Option C
Question 20. Variables affecting the rate of homogeneous reactions are
  1.    Pressure and temperature only
  2.    Temperature and composition only
  3.    Pressure and composition only
  4.    Pressure, temperature and composition
Answer: Option D