how can we without any calculation see if a solutions is ideal or non ideal? for exemple if you are given a sort of values for pressure and for each the vapour and liquid composition of a mixture how can we say if there is a ideal or non ideal solution? i'm getting crazy with this cause normally when i saw something about ideal solutions i always see some calculations, so how can i, only looking to values as i said above, say if a solution is non ideal or ideal? can be seen by dispertion of values? conjugation of values? how? maybe for some this question is too easy but after a week of electrochemistry i really have my brain stuck :S and i can't answer this. i didn't put this on homework section cause my main problem is the theory behind this, but if you see this is in the wrong section be free to move.