When a system is in equilibrium for all possible processes, the differential or finite change of entropy is__________________?

Related Mcqs:

1. Steam undergoes isentropic expansion in a turbine from 5000 kPa and 400°C (entropy = 6.65 kJ/kg K) to 150 kPa) (entropy of saturated liquid = 1.4336 kJ/kg. K, entropy of saturated vapour = 7.2234 kJ/kg. K) The exit condition of steam is_______________?

   A. Superheated vapour B. Partially condensed vapour with quality of 0.9 C. Saturated vapour D. Partially condensed vapour with quality of 0.1...

2. A system undergoes a change from a given initial state to a given final state either by an irreversible process or by a reversible process, then (where, Δ S1 and Δ SR are the entropy changes of the system for the irreversible and reversible processes respectively) ?

   A. Δ S1 is always Δ SR C. Δ S1 is always > Δ SR D. Δ S1 is always = Δ SR...

3. A solid metallic block weighing 5 kg has an initial temperature of 500°C. 40 kg of water initially at 25°C is contained in a perfectly insulated tank. The metallic block is brought into contact with water. Both of them come to equilibrium. Specific heat of block material is 0.4 kJ.kg-1. K-1. Ignoring the effect of expansion and contraction and also the heat capacity to tank, the total entropy change in kJ.kg-1, K-1 is_________________?

   A. -1.87 B. 0 C. 1.26 D. 3.91...

4. “When a system in equilibrium is subjected to a change in temperature, pressure or concentration, the equilibrium is displaced in a direction which tends to undo the effect of the change.” This is called the_______________?

   A. Le-Chatelier principle B. Kopp’s rule C. Law of corresponding state D. Arrhenius hypothesis...

5. Entropy change for an irreversible isolated system is__________________?

   A. ∞ B. 0 C. < 0 D. > 0...

6. High pressure steam is expanded adiabatically and reversibly through a well insulated turbine, which produces some shaft work. If the enthalpy change and entropy change across the turbine are represented by ΔH and ΔS respectively for this process ?

   A. Δ H = 0 and ΔS = 0 B. Δ H ≠ 0 and ΔS = 0 C. Δ H ≠ 0 and ΔS ≠ 0 D. Δ H = 0 and ΔS ≠ 0...

7. A system is said to be at equilibrium, if the entropy of the system has reached ____________ value?

   A. Minimum B. Zero C. Maximum D. None of these...

8. The expression for entropy change given by, ΔS = nR ln (V2/V1) + nCv ln (T2/T1) is valid for ______________________?

   A. Reversible isothermal volume change B. Heating of a substance C. Cooling of a substance D. Simultaneous heating and expansion of an ideal gas...

9. Entropy change for an irreversible process taking system and surrounding together is___________________?

   A. 0 B. > 0 C. < 0 D. None of these...

10. Entropy change of the reaction, H2O (liquid) → H2O (gas), is termed as the enthalpy of___________________?

    A. Solution B. Vaporisation C. Formation D. Sublimation...