Questions

Q and w are path functions while q+w i.e. H, enthalpy is state function. Similarly, H-TS i.e. G, Gibbs free energy is state function.

‘Sitting on the fence’ is the correct idiom used. It is used to describe a person’s lack of decisiveness, neutrality or hesitance to choose between two sides in an argument or a competition, or inability to decide due to lack of courage. Thus, the sentence is grammatically and contextually correct. Thus, the correct formation would be, ‘Decide one way or the other; you can’t be sitting on the fence forever’.