What is the value of ln y (where y = activity co-efficient) for ideal gases ?

Related Mcqs:

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

   A. 0
   B. 1
   C. 1

2. Free energy, fugacity and activity co-efficient are all affected by change in the temperature. The fugacity co-efficient of a gas at constant pressure ______________ with the increase of reduced temperature?

   A. Decreases
   B. Increases
   C. Remains constant
   D. Decreases logarithmically

3. For an ideal gas, the activity co-efficient is_________________?

   A. Directly proportional to pressure
   B. Inversely proportional to pressure
   C. Unity at all pressures
   D. None of these

4. 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

5. Joule-Thomson co-efficient which is defined as, η = (∂T/∂P)H = 1/Cp (∂H/∂T)P, changes sign at a temperature known as inversion temperature. The value of Joule-Thomson co-efficient at inversion temperature is ___________________?

   A. 0
   B. ∞
   C. +ve
   D. -ve

6. What is the value of Joule-Thomson co-efficient for an ideal gas ?

   A. +ve
   B. -ve
   C. 0
   D. ∞

7. Near their critical temperatures, all gases occupy volumes _____________ that of the ideal gas?

   A. Less than
   B. Same as
   C. More than
   D. Half

8. Compressibility factor (i.e., the ratio of actual volume of gas to the volume predicted by ideal gas law) for all gases are_______________?

   A. Always greater than one
   B. Same at the same reduced temperature
   C. Same at the same reduced pressure
   D. Both B. & C

9. Pressure-enthalpy chart is useful in refrigeration. The change in internal energy of an ideal fluid used in ideal refrigeration cycle is_____________________?

   A. Positive
   B. Negative
   C. Zero
   D. Infinity

10. ______________ Equation predicts the activity co-efficient from experimental data ?

    A. Lewis-Randall
    B. Margules
    C. Van Laar
    D. Both B. & C.