can someone help me solve this question. im not sure how to start so even some guidance would be helpful. thanks!

One mole of O2(g) undergoes the following change in state.

O2(g, 299 K, 4.38 bar) ⟶ O2(g, 252 K, 6.79 bar)

What is ΔS for the gas? Assume ideal gas behaviour.

The constant pressure molar heat capacity for O2(g) is Cp,m = 29.10 J K−1 mol−1.

I suppose I'm confused because I don't see a change of state. Both starting and ending states are gaseous.