The entropy of wet steam is illustrated by the image below.

To compute for entropy of wet steam, three essential parameters are needed and these parameters are **Entropy of Water (S _{f}), Enthalpy of Vapourisation (h_{fg})** and

**Saturated Temprature (T**

_{s}).The formula for calculating entropy of wet steam:

S_{g} = S_{f} + ^{hfg} / _{Ts}

Where:

S_{g} = Entropy of Wet Steam

S_{f} = Entropy of Water

h_{fg} = Enthalpy of Vapourisation

T_{s} = Saturated Temprature

Given an example;

Find the entropy of wet steam when the entropy of water is 12, the enthalpy of vapourisation is 10 and the saturated temperature is 14.

This implies that;

S_{f} = Entropy of Water = 12

h_{fg} = Enthalpy of Vapourisation = 10

T_{s} = Saturated Temprature = 14

S_{g} = S_{f} + ^{hfg} / _{Ts}

S_{g} = 12 + ^{10} / _{14}

S_{g} = 12 + 0.714

S_{g} = 12.71

Therefore, the **entropy of wet steam **is **12.71 J/K.**

**Calculating the Entropy of Water when the Entropy of Wet Steam, the Entropy of Vapourization and the Saturated Temperature is Given.**

S_{f} = (S_{g} x T_{s}) – h_{fg}

Where:

S_{f} = Entropy of Water

S_{g} = Entropy of Wet Steam

h_{fg} = Enthalpy of Vapourisation

T_{s} = Saturated Temprature

Let’s solve an example;

Find the entropy of water when the entropy of wet steam is 10, the enthalpy of vapourization is 5 and the saturated temperature is 2.

This implies that;

S_{g} = Entropy of Wet Steam = 10

h_{fg} = Enthalpy of Vapourisation = 5

T_{s} = Saturated Temprature = 2

S_{f} = (S_{g} x T_{s}) – h_{fg}

S_{f} = (10 x 2) – 5

S_{f} = 20 – 5

S_{f} = 15

Therefore, the **entropy of water **is **15.**

Continue reading How to Calculate and Solve for Entropy of Wet Steam | Enthalpy