58. A throttling calorimeter is connected to a desuperheated steam line supplying steam to the

auxiliary feed pump on a ship. The line pressure measures 2.5 MPa. The calorimeter pressure is

110 kPa at 150°C. Determine the entropy of the steam line.

@ 110 kPa and 150°C: h2 = 2775.6 kJ/kg

@ 2.5 MPa: hf = 962.11 kJ/kg hfg = 1841 kJ/kg

sf = 2.5547 kJ/kg-K sfg = 3.7028 kJ/kg-K

A. 6.8 kJ/kg-K

B. 6.2 kJ/kg-K

C. 6.6 kJ/kg-K

D. 7.5 kJ/kg-K