Specific _____________ does not change during phase change at constant temperature and pressure?

Related Mcqs:

1. Specific ____________ does not change during a phase change (e.g. sublimation, melting, vaporisation etc.)?

   A. Entropy
   B. Internal energy
   C. Enthalpy
   D. Gibbs free energy

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. Gibbs-Duhem equation relates composition in liquid phase and the _____________ at constant temperature & pressure?

   A. Fugacity
   B. Partial pressure
   C. Activity co-efficient
   D. All (A), (B), and (C)

4. For a stable phase at constant pressure and temperature, the fugacity of each component in a binary system _____________ as its mole fraction increases?

   A. Decreases
   B. Increases
   C. Remain same
   D. Decreases linearly

5. While dissolving a gas into a liquid at a constant temperature, the ratio of the concentration of the gas in the solution phase and in the gaseous phase is _______________?

   A. Infinity
   B. Unity
   C. Constant
   D. Negative

6. The vapour pressure of water is given by, in Psat = A – (5000/T), where A is a constant, Psat is the vapour pressure in atm. and T is the temperature in K. The vapor pressure of water in atm. at 50°C is approximately__________________?

   A. 0.07
   B. 0.09
   C. 0.11
   D. 0.13

7. 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

8. In reactions involving solids and liquids (where change in volume is negligible), the heat of reaction at constant pressure as compared to that at constant volume is_______________?

   A. More
   B. Less
   C. Same
   D. Unpredictable; depends on the particular reaction

9. The chemical potential of a component (μi) of a phase is the amount by which its capacity for doing all work, barring work of expansion is increased per unit amount of substance added for an infinitesimal addition at constant temperature and pressure. It is given by_________________?

   A. (∂E/∂ni)S, v, nj
   B. (∂G/∂ni)T, P, nj = (∂A/∂ni) T, v, nj
   C. (∂H/∂ni)S, P, nj
   D. All (A), B. and (C)

10. 1m3 of an ideal gas at 500 K and 1000 kPa expands reversibly to 5 times its initial volume in an insulated container. If the specific heat capacity (at constant pressure) of the gas is 21 J/mole . K, the final temperature will be ?

    A. 35 K
    B. 174 K
    C. 274 K
    D. 154 K