Entropy at a constant pressure?

Question

What equation do I use to find entropy at a constant pressure?

I found one equation online but it doesn't seem to be correct.

please help! thanks.

Answer 1

There are a few equations that allow the calculation of entropy

S = integral Cp/T dT  is the obvious one

S = k ln W

S = U/T + k ln Q

Remember S is an absolute value a perfect crystal at zero kelvin has S = 0.