@acer 

But how could I calculate the Ag2O's "Molar specific enthalpy"  with ”Hmolar“ command?

@dharr 

Thank you. It seems it's a good way to learn thermo from maple.

@dharr 

Thanks.

Sorry for my rookie hand. I am indeed to find a function to find the delta energy( which W stands for). For instance , in my case, the thermo problem is calculated as ( Vapor seemed as ideal,Condensing process treated as under constant pressure)

W=-P*Delta Volume=-p[V(1)-V(g)]=pV(g)=n(g)RT=3.102kJ

I wonder if there is a function like Hmolar,Smolar that I can calculate to find the Delta Energy.

@vv This indeed very much helps.Thank you so much.

@Carl Love Thank you.Mea culpa. I forgot the very fundamental quality of the continuous.