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 ?

Question

Accepted Answer

Δ H ≠ 0 and ΔS = 0. For an adiabatic process, the entropy change (ΔS) is zero only if the process is reversible. Since work is produced, there must be an enthalpy change (ΔH ≠ 0). Therefore, ΔH ≠ 0 and ΔS = 0.