For a constant pressure reversible process, the enthalpy change (ΔH) of the system is___________________?

Related Mcqs:

1. On a P-V diagram of an ideal gas, suppose a reversible adiabatic line intersects a reversible isothermal line at point A. Then at a point A, the slope of the reversible adiabatic line (∂P/∂V)s and the slope of the reversible isothermal line (∂P/∂V)T are related as (where, y = Cp/Cv) ?

   A. (∂P/∂V)S = (∂P/∂V)T
   B. (∂P/∂V)S = [(∂P/∂V)T]Y
   C. (∂P/∂V)S = y(∂P/∂V)T
   D. (∂P/∂V)S = 1/y(∂P/∂V)T

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. 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. Enthalpy of formation of NH3 is – 46 kJ/kg mole. The enthalpy change for the gaseous reaction, 2NH3 → N2 + 3H2, is equal to _____________ kJ/kg. mole?

   A. 46
   B. 92
   C. -23
   D. -92

5. The expression for the work done for a reversible polytropic process can be used to obtain the expression for work done for all processes, except reversible _____________ process?

   A. Isobaric
   B. Isothermal
   C. Adiabatic
   D. None of these

6. Enthalpy changes over a constant pressure path are always zero for ______________ gas?

   A. Any
   B. A perfect
   C. An easily liquefiable
   D. A real

7. 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

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

   A. +ve
   B. 0
   C. -ve
   D. ∞

9. 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

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

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