# Isobaric Process - Entropy in Terms of Pressure and Volume

Isobaric process is a thermodynamic process where the pressure is kept constant, \(\Delta p = 0\).

### Isobaric process - entropy in terms of pressure and volume Formula

\(\large{ S = \Delta S \; \left( - n\; R \right) \; \left[ ln \left( \frac{p_f}{p_i} \right) \right] }\)

\(\large{ S = \Delta S \; \left( n\; R \right) \; \left[ ln \left( \frac{V_f}{V_i} \right) \right] }\)

Where:

\(\large{ S }\) = entropy

\(\large{ \Delta S }\) = change in entropy

\(\large{ R }\) = molar gas constant

\(\large{ ln }\) = natural logarithm

\(\large{ n }\) = number of moles

\(\large{ p_f }\) = final pressure

\(\large{ V_f }\) = final volume

\(\large{ p_i }\) = final pressure

\(\large{ V_i }\) = initial volume

Tags: Equations for Pressure Equations for Volume Equations for Entropy