In a homogeneous solution, the activity co-efficient of a component depends upon the_________________?

Related Mcqs:

1. Fugacity of a component in an ideal gas mixture is equal to the partial pressure of that component in the mixture. The fugacity of each component in a stable homogeneous solution at constant pressure and temperature ____________ as its mole fraction increases?

   A. Decreases
   B. Decreases exponentially
   C. Increases
   D. Remain constant

2. In a homogeneous solution, the fugacity of a component depends upon the __________________?

   A. Pressure
   B. Composition
   C. Temperature
   D. All (A), B. and (C)

3. The activity co-efficient of a solution, which accounts for the departure of liquid phase from ideal solution behaviour________________?

   A. Measures the elevation in boiling point
   B. Is not dependent on the temperature
   C. Is a function of the liquid phase composition
   D. Measures the depression in freezing point

4. 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

5. Entropy change of mixing two liquid substances depends upon the_________________?

   A. Molar concentration
   B. Quantity (i.e. number of moles)
   C. Both A. and B
   D. Neither A. nor B

6. In an ideal solution, the activity of a component equals its __________________?

   A. Mole fraction
   B. Fugacity at the same temperature and pressure
   C. Partial pressure
   D. None of these

7. The molar excess Gibbs free energy, gE, for a binary liquid mixture at T and P is given by, (gE/RT) = A . x1. x2, where A is a constant. The corresponding equation for ln y1, where y1 is the activity co-efficient of component 1, is__________________?

   A. A . x22
   B. Ax1
   C. Ax2
   D. Ax12

8. At 60° C, vapour pressure of methanol and water are 84.562 kPa and 19.953 kPa respectively. An aqueous solution of methanol at 60° C exerts a pressure of 39.223 kPa; the liquid phase and vapour phase mole fractions of methanol are 0.1686 and 0.5714 respectively. Activity co-efficient of methanol is__________________?

   A. 1.572
   B. 1.9398
   C. 3.389
   D. 4.238

9. For an ideal solution, the value of activity co-efficient is______________________?

   A. 0
   B. 1
   C. 1

10. According to Raoult’s law, “The vapor pressure exerted by component in a solution is proportional to the mole fraction of that component.” Raoult’s law is not applicable under the following assumption/condition?

    A. No component is concentrated at the surface of the solution
    B. The component molecules are non polar and are of almost equal size
    C. In the formation of solution, chemical combination/molecular association between unlike
    molecules takes place
    D. The attractive forces between like and unlike molecules are almost equal