Chemical Engineering - Chemical Engineering Thermodynamics - Discussion

Entropy of ideal gas is function of both temperature and pressure since.

Delta S = Cp ln(T2/1)-R ln(P2/P1).

Besides as gas behaves ideal at low pressure and high temperature.

So Enthalpy is very weak function of pressure and strong function of temperature.

Entropy of an ideal gas is defined as:

delta S= (nCv ln(T2/T1))+(nR ln(V2/V1)).

or

delta S= (nCv ln(P2/P1))+(nR ln(V2/V1)) .

Since P and T are related by as P/T= constant for ideal gas.

Entropy is a measure of disorder ness of molecules. For crystalline material entropy is zero. Example ice cube.
In the ice cube the arrangement of molecules are in uniform manner, so entropy is zero.
If you heat the ice cube the arrangement of molecules will change and the value of entropy will increases.
So here temperature is one factor and same as pressure also one factor.
So entropy is depend on both temp and presusre.

Only B is the correct option.