> May I pull you up at this point please? Alcohol (ethanol) is NOT easier
> to condense because of its lower heat of vaporization. A vapor mix
> behaves as one unit with a boiling point (hence condensation point)
> determined by the composition. You can work out the heat given up in
> condensing by calculating the relative quantities of ethanol at 204
> cal.gm and water at 540 cal/gm, but they BOTH condense together, not one
> in preference to the other.
Fair enough Mike. I hesitate to get into a discussion a few minutes before
taking off for a distillate-assisted camping weekend, but I was trying to
suggest in a shorthand sort of way that once he had some alcohol in the
equation, the condenser's work would be reduced proportionally.
At the same time, though, my limited experience and common sense tells me
that the lower the boiling point of the liquid, the harder it is to coerce
into condensing. I've noticed that I seem to get some trace (and very
fragrant) volatiles wafting off my boiler at anywhere from 20 deg C
upwards. These, with their boiling points so close to the temperature of
the cooling water, seem unimpressed by it and often continue on their merry
way out the vent hole. So if the same principle applies to ethanol it might
partially cancel out any theoretical advantage conferred by its lower heat
of evaporation. In other words, cooling water at 20C can only offer ethanol
58 degrees worth of incentive to condense, whereas it can offer water 80
degrees. In other words, it can do more [negative] work on the water.
Is this vaguely sensible?
My apologies for delayed replies.