Why doesn't it like my expressions?

I don't understand why it doesn't like my ∆H expressions (the one that use heat capacity). I'm talking about ∆Hethanol(T), ∆Hethylene(T) and ∆Hwater(T). From there I think I can figure out what's wrong with the rest of it, just need to know one to know the rest. It doesn't come up as red until you enter the = sign.

Also, do I need to do a solve block before ∆Greaction(T,P,e) to get it to graph? I just can't tell because of the errors.