During crystallisation, formation of crystal can occur in ______________ solution only?

Related Mcqs:

1. The driving potential for the crystal growth during crystallisation is the _______________ of the solution?

   A. Concentration
   B. Viscosity
   C. Super-saturation
   D. Density

2. It is desired to concentrate a 20% salt solution (20 kg of salt in 100 kg of solution) to a 30% salt solution in an evaporator. Consider a feed of 300 kg/min at 30°C. The boiling point of the solution is 110°C, the latent heat of vaporisation is 2100 kJ/kg and the specific heat of the solution is 4 kJ/kg.K. The rate at which the heat has to be supplied in (kJ/min) to the evaporator is____________________?

   A. 3.06 × 105
   B. 6.12 × 105
   C. 7.24 × 105
   D. 9.08 × 105

3. In case of a super-cooled solution, which is on the verge of crystallisation, the free energy of the solution as compared to that of the solid is ________________?

   A. More
   B. Less
   C. Same
   D. More or less; depends on the nature of solution

4. Crystallisation of solids from a homogeneous solution is a/an ______________ process?

   A. Exothermic
   B. Mildly endothermic
   C. Highly endothermic
   D. None of these

5. Boiling point elevation for a strong and concentrated solution is found by Duhring’s rule, which states that at the same pressure, the boiling point of a solution is a linear function of the _______________ of pure water?

   A. Boiling point
   B. Dynamic viscosity
   C. Kinematic viscosity
   D. Density

6. Crystal size in a continuous crystalliser depends upon the___________________?

   A. Rate of heat transfer
   B. Degree of turbulence
   C. Degree of super-saturation
   D. All A., B. and C

7. The most conducive surface for dropwise condensation to occur is the _____________ surface?

   A. Coated
   B. Oily
   C. Glazed & polished
   D. Smooth

8. Boiling point of a solution according to Duhring’s rule is a linear function of the _____________ of water?

   A. Boiling point (at the same pressure)
   B. Viscosity
   C. Density
   D. Thermal conductivity

9. A process stream of dilute aqueous solution flowing at the rate of10 Kg.s-1 is to be heated. Steam condensate at 95°C is available for heating purpose, also at a rate of 10 Kg.s-1. A 1 – 1 shell and tube heat exchanger is available. The best arrangement is_______________?

   A. Counter flow with process stream on shell side
   B. Counter flow with process stream on tube side
   C. Parallel flow with process stream on shell side
   D. Parallel flow with process stream on tube side

10. Which is the most suitable for the concert-ration of highly concentrated solution ?

    A. Open pan evaporation
    B. Long tube vertical evaporator
    C. Agitated film evaporator
    D. None of these