Space time equals the mean residence time__________________?

Related Mcqs:

1. Mean residence time is equal to the space time, when_________________?

   A. The feed rate is measured at temperature and pressure in the reactor
   B. The temperature, pressure and the density of reaction mixture remains constant throughout the
   reactor
   C. There is no change in number of moles in gaseous reaction
   D. All A., B. and C.

2. The use of space time is preferred over the mean residence time in the design of a/an____________________?

   A. Batch reactor
   B. Ideal tubular-flow reactor
   C. Slurry reactor
   D. CSTR

3. When the density of the reaction mixture is constant in a chemical reaction, the ratio of the mean residence time to space time is__________________?

   A. > 1
   B. < 1
   C. 1
   D. 0

4. A pulse tracer is introduced in an ideal CSTR (with a mean residence time I) at time, t = 0. The time taken for the exit concentration of the tracer to reach half of its initial value will be__________________?

   A. 2η
   B. 0.5η
   C. η/0.693
   D. 0.693η

5. For a tubular reactor with space time ‘η’ and residence time ‘ζ’, the following statement holds good ?

   A. η and θ are always equal
   B. η = θ, when the fluid density changes in the reactor
   C. η = θ, for an isothermic tubular reactor in which the density of the process fluid is constant
   D. η = θ, for a non-isothermal reactor

6. 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

7. The exit age distribution curve E(t) for an ideal CSTR with the average residence time, η, is given by__________________?

   A. e-t/η
   B. e-t/η/η
   C. 1 – e-t/η
   D. 1 – (e-t/η/η)

8. For a packed bed reactor; the presence of a long tail in the residence time distribution curve is an indication of ?

   A. Ideal plug flow
   B. Bypass
   C. Dead zone
   D. Channelling

9. For the same residence time, which one will give the maximum conversion ?

   A. Single stirred tank (v = 5 litres)
   B. Two stirred tank (each of 2.5 litres) in series
   C. Stirred tank followed by tubular flow reactor (each of 2.5 litres)
   D. Single tubular flow reactor (v = 5 litres)

10. The conversion XA and residence time data are collected for zero order liquid phase reaction in a stirred tank reactor. Which of the following will be a straight line ?

    A. XA Vs . η
    B. XA Vs ln η
    C. XA/(1 – XA)Vs η
    D. XA(1 – XA)Vs η