The reaction A (l) → R(g) is allowed to reach equilibrium conditions in an autoclave. At equilibrium, there are two phases, one a pure liquid phase of A and the other a vapor phase of A, R and S. Initially A alone is present. The numbers of degrees of freedom are ?

Related Mcqs:

1. A reasonably general expression for vapour-liquid phase equilibrium at low to moderate pressure is φi yi P = Yi xifi° where, Φ is a vapor fugacity component, Yi is the liquid activity coefficient and fi° is the fugacity of the pure component i. the Ki value (Yi = Ki xi) is therefore, in general a function of ______________________?

   A. Temperature only
   B. Temperature and pressure only
   C. Temperature, pressure and liquid composition xi only
   D. Temperature, pressure, liquid composition xi and vapour composition yi

2. What is the number of degrees of freedom for liquid water in equilibrium with a mixture of nitrogen and water vapor ?

   A. 2
   B. 0
   C. 3
   D. 1

3. The ratio of existing moles of vapor per mole of vapor free gas to the moles of vapor that would be present per mole of vapor free gas, if the mixture were saturated at the existing temperature & pressure, is termed as the_____________________?

   A. Relative humidity
   B. Relative saturation
   C. Percentage saturation
   D. None of these

4. The vapor pressures of benzene and toluene are 3 and 4/3 atmospheres respectively. A liquid feed of 0.4 moles of benzene and 0.6 moles of toluene is vaporised. Assuming that the products are in equilibrium, the vapor phase mole fraction of benzene is_________________?

   A. 0.4
   B. 0.6
   C. 0.8
   D. 0.2

5. Number of degrees of freedom for a three phase system in equilibrium comprising of three non-reacting chemical species is__________________?

   A. 2
   B. 0
   C. 1
   D. 3

6. Number of components (C), phase (P) and degrees of freedom (F) are related by Gibbs phase rule as________________?

   A. P + F – C = 2
   B. C = P – F + 2
   C. F = C – P – 2
   D. P = F – C – 2

7. The molecules of a liquid which is in equilibrium with its vapor at its boiling point on an average have equal _____________ in the two phases?

   A. Potential energy
   B. Intermolecular forces
   C. Kinetic energy
   D. Total energy

8. What is the degree of freedom for two miscible (non-reacting) substances in vapor-liquid equilibrium forming an azeotrope ?

   A. 0
   B. 1
   C. 2
   D. 3

9. What is the number of degree of freedom for a system of two miscible non-reacting species in vapor-liquid equilibrium forming an azeotrope ?

   A. 0
   B. 2
   C. 1
   D. 3

10. For multi-component multiple phases to be in equilibrium at the same pressure and temperature, the _______________ of each component must be same in all phases?

    A. Chemical potential
    B. Fugacity
    C. Both A. and B
    D. Neither A. nor B