Comment by alwa

I mean—depending how much methanol was in the mix to begin with…

It’s been a long time, but I thought there was a whole Raoult’s Law thing, about partial pressures in the vapor coming off the solution combining in proportion to each component’s molar fraction * its equilibrium vapor pressure (at that temperature, presumably). Or something.

Point being, if you’re starting with a bunch of volatiles in solution, there’d be quite a bit of smearing between fractions boiling off at any given temperature/pressure. And you’d be very unlikely to get clean fractions from a single distillation anywhere in that couple-dozen-degree range.

Probably mangled the description, but isn’t that why people do reflux columns?