Recycling back of outlet stream to the reactor from an ideal CSTR carrying out a first order liquid phase reaction will result in ______________ in conversion?

Related Mcqs:

1. The conversion for a first order liquid phase reaction. A → B in a CSTR is 50%. If another CSTR of the same volume is connected in series, then the % conversion at the exit of the second reactor will be_____________________?

   A. 60
   B. 75
   C. 90
   D. 100

2. For the liquid phase zero order irreversible reaction A → B, the conversion of A in a CSTR is found to be 0.3 at a space velocity of 0.1min-1. What will be the conversion for a PFR with a space velocity of 0.2 min-1? Assume that all the other operating conditions are the same for CSTR and PFR ?

   A. 0.15
   B. 0.30
   C. 0.60
   D. 0.90

3. The gas phase reaction 2A ⇌ B is carried out in an isothermal plug flow reactor. The feed consists of 80 mole % A and 20 mole % inerts. If the conversion of A at the reactor exit is 50%, then CA/CA0 at the outlet of the reactor is _______________________?

   A. 2/3
   B. 5/8
   C. 1/3
   D. 3/8

4. A liquid phase reaction is to be carried out under isothermal conditions. The reaction rate as a function of conversion has been determined experimentally and is shown in the figure given below. What choice of reactor or combination of reactors will require the minimum overall reactor volume, if a conversion of 0.9 is desired ?

   A. CSTR followed by a PFR
   B. PFR followed by a CSTR
   C. CSTR followed by a PFR followed by a CSTR
   D. PFR followed by a CSTR followed by a PFR

5. A second order liquid phase reaction, A → B, is carried out in a mixed flow reactor operated in semi batch mode (no exit stream). The reactant A at concentration CAF is fed to the reactor at a volumetric flow rate of F. The volume of the reacting mixture is V and the density of the liquid mixture is constant. The mass balance for A is_______________________?

   A. d(VCA)/dt = -F (CAF – CA) – kCA2V
   B. d(VCA)/dt = F (CAF – CA) – kCA2V
   C. d(VCA)/dt = -FCA – kCA2V
   D. d(VCA)/dt = FCAF – kCA2V

6. 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_________________?

   A. 2/3 kW
   B. 1 kW
   C. 5/3 kW
   D. 4 kW

7. The following gas phase reaction is taking place in a plug flow reactor. A stoichiometric mixture of A and B at 300 K is fed to the reactor. At 1 m along the length of the reactor, the temperature is 360 K. The pressure drop is negligible and an ideal gas behaviour can be assumed. Identify the correct expression relating the concentration of A at the inlet (CA0), concentration of A at 1m (CA) and the corresponding conversion of A (X) ?

   A. CA = 1.2 CA0 (1 – X)/(1 – 0.33X)
   B. CA = 1.2 CA0 (1 – X)/(1 – 0.5X)
   C. CA = 0.83 CA0 (1 – X)/(1 – 0.33X)
   D. CA = 0.83 CA0 (1 – X)/(1 – 0.5X)

8. An isothermal aqueous phase reversible reaction, P ⇌ R, is to be carried out in a mixed flow reactor. The reaction rate in k.mole/m3 .h is given by, r = 0.5CP – 0.125CR. A stream containing only P enters the reactor. The residence time required (in hours) for 40% conversion of P is_________________?

   A. 0.80
   B. 1.33
   C. 1.60
   D. 2.67

9. An irreversible aqueous phase reaction, A + B → P, is carried out in an adiabatic mixed flow reactor. A feed containing 4kmole/m3 of each A and B enters the reactor at 8m3 /hr. If the temperature of the exit stream is never to exceed 390 K, what is the maximum inlet feed temperature allowed? Data: Heat of reaction = – 50 kJ/mole Density of the reacting mixture = 1000kg/m3 Specific heat of reacting mixture = 2kJ/kg.K The above data can be assumed to be independent of temperature and composition?

   A. 190
   B. 290
   C. 390
   D. 490

10. With the same reaction time, initial concentration and feed rate, the reaction 2A → B is carried out separately in CSTR and P.F. reactor of equal volumes. The conversion will be__________________?

    A. Higher in P.F. reactor
    B. Higher in CSTR
    C. Same in both the reactors
    D. Data insufficient; can’t be predicted