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Chemical Engineering :: Chemical Reaction Engineering

  1. A catalyst loses its activity due to

  2. A.

     Loss in surface area of the active component

    B.

     Agglomeration of metal particles caused by thermal sintering of the solid surface

    C.

     Covering of the catalytic active sites by a foregin substance

    D.

     All of the above


  3. Which of the following resistances is not involved in a gas phase catalytic (gas- solid) reaction?

  4. A.

     Ash resistance

    B.

     Gas film and pore surface diffusion resistances for reactants

    C.

     Surface phenomenon resistance

    D.

     Gas film and pore surface diffusion resistances for products


  5. What is the dispersion number for a plug flow reactor?

  6. A.

     0

    B.

     ?

    C.

     1

    D.

     -1


  7. __________ resistance is not involved in the combustion of a carbon particle.

  8. A.

     Gas film

    B.

     Ash

    C.

     Chemical reaction

    D.

     None of these


  9. Pick out the wrong statement.

  10. A.

     The vessel dispersion number (D/UL) for plug flow and mixed flow approaches zero and infinity respectively

    B.

     Space time in a flow reactor is a measure of its capacity and is equal to the residence time when the density of reaction mixture is constant

    C.

     Mixed reactor is always smaller than the plug flow reactor for all positive reaction orders for a particular duty

    D.

     N an ideal tubular flow reactor, mixing takes place in radial direction and there is no mixing in logitudinal direction


  11. The excess energy of reactants in a chemical reaction required to dissociate into products is termed as the __________ energy.

  12. A.

     Activation

    B.

     Potential

    C.

     Binding

    D.

     Threshold


  13. Which of the following is used for calcination of limestone and dolomite in industrial practice?

  14. A.

     Fluidised bed reactor

    B.

     Moving bed reactor

    C.

     Fixed bed reactor

    D.

     None of these


  15. The reactions of high molecularity are rare, because

  16. A.

     Of very large activation energy of many bodies

    B.

     Of low probability of many body collisions

    C.

     Many body collisions are not favoured energetically

    D.

     Of requirement of very large concentration for such reactions


  17. Molecularity of a reaction

  18. A.

     Is always equal to the overall order of reaction

    B.

     May not be equal to the order of reaction

    C.

     Can

    D.

     Both B and C


  19. A CSTR is to be designed in which an exothermic liquid phase first order reaction of the type, A → R, is taking place. The reactor is to be provided with a jacket in which coolant is flowing. Following data is given: CA0= 5 kmole/m³ ; XA = 0.5; Feed temperature = reactor temperature = 40°C. Rate constant at 40°C = 1 min⁻¹ ; (ΔH) = - 40kJ/mole; ρ = 1000kg/m³ CP = 4 J/gm.°C ; q = 10⁻³ m³/min (ρ and CP are same for the reactant and product streams). The amount of heat to be removed is

  20. A.

     2/3 kW

    B.

     1kW

    C.

     5/3 kW

    D.

     4kW