Ideal Gas Entropy Change Calculator

Calculate the change in entropy for an ideal gas using:
\[ \Delta S = n\, C_p \ln\left(\frac{T_2}{T_1}\right) – n\, R \ln\left(\frac{P_2}{P_1}\right) \]

* Enter the number of moles, initial and final temperatures (K), and pressures (in atm). Select the gas type.

Step 1: Enter Conditions

Number of Moles, \( n \) (mol):

Example: 1 mol

Initial Temperature, \( T_1 \) (K):

Example: 298 K

Final Temperature, \( T_2 \) (K):

Example: 350 K

Initial Pressure, \( P_1 \) (atm):

Example: 1 atm

Final Pressure, \( P_2 \) (atm):

Example: 1 atm (if pressure remains constant)

Gas Type:

Select your gas type for appropriate \( C_p \).

Step 1: Enter Conditions

Calculated Entropy Change