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 ________________?

Related Mcqs:

1. 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

2. 200 kg of solids (on dry basis) is subjected to a drying process for a period of 5000 seconds. The drying occurs in the constant rate period with the drying rate as, Nc = 0.5 × 10-3 kg/m2.s. The initial moisture content of the solid is 0.2 kg moisture/kg dry solid. The interfacial area available for drying is 4 m2/1000 kg of dry solid. The moisture content at the end of the drying period is (in kg moisture/kg dry solid)?

   A. 0.5
   B. 0.05
   C. 0.1
   D. 0.15

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

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

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

   A. Saturated
   B. Supersaturated
   C. Under-saturated
   D. All A., B. and C.

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

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

6. Heat transfer by conduction results due to the transfer of free electrons, kinetic energy & vibrational energy from one molecule to another. Conduction heat transfer cannot take place____________________?

   A. Between two bodies in physical contact with each other
   B. Between two bodies not in physical contact with each other
   C. From one part of a body to the another part of the same body
   D. Both B & C

7. 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

8. A hollow sphere and a solid sphere of the same material and equal radii are heated to the same temperature. In this case ?

   A. The cooling rate will be the same for the two spheres and hence the two spheres will have
   equal temperatures at any instant
   B. Both the spheres will emit equal amount of radiation per unit time in the beginning
   C. Both will absorb equal amount of radiation from the surrounding in the beginning
   D. Both B. & C.

9. In sub-cooled boiling ?

   A. Temperature of the heating surface is less than the boiling point of the liquid
   B. Temperature of the heating surface is more than the boiling point of the liquid
   C. Bubbles from heating surface are absorbed by the mass of the liquid
   D. Very large vapour space is necessary

10. Mode of heat transfer involved in the cooling of air cooled internal combustion engine is_________________?

    A. Conduction
    B. Natural convection
    C. Forced convection
    D. None of these