water is at a pressure of 3 bars with an enthalpy of 2600 kj

water is at a pressure of 3 bars with an enthalpy of 2600 kj/kg. what is its entropy?

Solution

>> At, Pressure, P = 3 bar,

From Steam Table,

hg = 2724.8917 KJ/Kg

sg = 6.9916 KJ/Kg-K

and,

hf = 561.4554 KJ/Kg

sf = 1.6718 KJ/Kg-K

As, h = 2600 KJ/Kg = hf + x*(hg - hf)

=> 2600 = 561.4554 + x*(2724.8917 - 561.4554)

=> x = 0.9423

So, Required Entropy, s = sf + x*(sg - sf)

=> s = 1.6718 + 0.9423*(6.9916 - 1.6718)

=> s = 6.6845 KJ/Kg-K   ........ANSWER........