S there a way to calculate this using the thermodynamic identity?

[Shaybay92]

Homework Statement

A liter of air, initially at room temperature and atmospheric pressure, is heated at constant pressure until it doubles in volume. Calculate the increase in its entropy during this process.

Is there a way to calculate this using the thermodynamic identity (ie. without the Sackur Tetrode equation??) I was trying to use this formula, setting dV = V_initial... Any ideas?

dS = (dS/dU)dU + (dS/dV)dV

 

[Andrew Mason]

Homework Statement

A liter of air, initially at room temperature and atmospheric pressure, is heated at constant pressure until it doubles in volume. Calculate the increase in its entropy during this process.

Is there a way to calculate this using the thermodynamic identity (ie. without the Sackur Tetrode equation??) I was trying to use this formula, setting dV = V_initial... Any ideas?

dS = (dS/dU)dU + (dS/dV)dV

What is the matter with:

$$\Delta S = \int dQ_{rev}/T = nC_p\ln(T_f/T_i) ?$$

AM