This is for my Chemical Engineering class, but it comes down to a thermodynamics question. I need to calculate the gibbs free energy for a few reactions, problem is some of the compounds (1-Buten-3-yne and Styrene) do not have standard entropy values that I can find. Without a standard entropy I cannot calculate the gibbs free energy as a function of temperature. I know they have to be out thre somewhere but I cannot find after extensive googling. Can anyone point me in the right direction?