Entropy of a substance remains constant during a/an ____________ change?

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. The expression for entropy change, ΔS = n Cp . ln (T2/T1), is valid for the ______________ of a substance?

   A. Simultaneous pressure & temperature change B. Heating C. Cooling D. Both B. and C...

3. 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...

4. 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...

5. During a reversible isothermal expansion of an ideal gas, the entropy change is_________________?

   A. +ve B. 0 C. -ve D. ∞...

6. During a reversible isothermal expansion of an ideal gas, the entropy change is___________________?

   A. +ve B. 0 C. -ve D. ∞...

7. “At the absolute zero temperature, the entropy of every perfectly crystalline substance becomes zero”. This follows from the __________________?

   A. Third law of thermodynamics B. Second law of thermodynamics C. Nernst heat theorem D. Maxwell’s relations...

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

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

9. _____________________ remains constant during the adiabatic cooling of moist air?

   A. Wet bulb temperature B. Dry bulb temperature C. Relative humidity D. Specific humidity...

10. 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...