[Kalibasa]

We performed distillations in lab, and I've attached the graphs of recorded temperature vs. distillate volume (there are only two). My TA wasn't there today and I want to make sure I'm interpreting these right.

1) The water/ethanol one closely matches the one in my lab guide for simple vs. fractional distillation, so I think those data look quite good. Our guide tells us that these curves "provide information as to the efficiency of the separation of the components in a mixture," and the sharp jump on the fractional distillation makes sense to me. But I'm not sure how to account for the gradual slope on the simple distillation. Does it just mean that both the ethanol and the water were boiling off at those intermediate temperatures, rather than having them boil off at different times? I figured that water could be boiling off below 100 C here because the presence of the ethanol would give the solution a greater combined vapor pressure.

2) For the cyclohexane-toluene graph, I'm wondering if anyone has any idea why the data seem so screwy. I didn't do these two procedures myself, so I don't what the possible mistakes could have been.  At this point I was just going to point out the same things as above- the gradual rise for the simple distillation vs. a sharper jump in the fractional distillation. But I do feel I need to address why the boiling points are so off!

(FYI, the boiling point of pure ethanol is 78.5 C, the boiling point of cyclohexane is 81 C, and the boiling point of toluene is 110.6 C).

Sorry this is so long. Thank you!