Any substance above its critical temperature exists as _____________________?

Related Mcqs:

1. Chemical potential (an intensive property) of a substance is a force that drives the chemical system to equilibrium and is equal to its partial molar properties. The ratio of chemical potential to free energy of a pure substance at constant temperature and pressure is________________?

   A. 0
   B. 1
   C. ∞
   D. None of these

2. Critical temperature is defined as the temperature above which a gas will____________________?

   A. Not liquify (barring exceptions)
   B. Immediately liquify
   C. Never liquify however high the pressure may be
   D. None of these

3. A gas can be liquefied by pressure alone only, when its temperature is _____________ its critical temperature?

   A. Less than
   B. More than
   C. Equal to or higher than
   D. Less than or equal to

4. Critical solution temperature (or the con-solute temperature) for partially miscible liquids (e.g., phenol-water) is the minimum temperature at which___________________?

   A. A homogeneous solution (say of phenol water) is formed
   B. Mutual solubility of the two liquids shows a decreasing trend
   C. Two liquids are completely separated into two layers
   D. None of these

5. 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)

6. Cp of a gas at its critical temperature and pressure_______________?

   A. Becomes zero
   B. Becomes infinity
   C. Equals 1 kcal/kmol °K
   D. Equals 0.24 kcal/kmol °K

7. Absorption/evolution of heat during conversion of a substance from one allotropic form to another is termed as the heat of _____________________?

   A. Sublimation
   B. Fusion
   C. Transition
   D. Vaporisation

8. All gases above its inversion temperature, in a throttling process will show__________________?

   A. A heating effect
   B. No change in temperature
   C. A cooling effect
   D. Either A. or (C)

9. 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

10. For a given substance at a specified temperature, activity is ______________ to fugacity?

    A. Directly proportional
    B. Inversely proportional
    C. Equal
    D. None of these