What is present during the following times of the Dumas procedure

[Zoey Brown]

From the list below, identiyfy what is present in the flask at each of the following times during the Dumas procedure performed with methanol:
Methanol (g)
Methanol (l)
Methanol (aq)
Air (g)
Water (l)
Water (g)

a) After the methanol is added and the flask is covered with foil?
b) Just before the flask is removed from the hot water bath?
c) When the flask is weighted after cooling?

My solution:
a) i think this would be methanol (l) and air (g) bc there is no evidence that methanol is in aq form
b) i think this would be methanol (g) bc all the air is expelled and the methanol is vapourized
c) this one i have no clue and don't even know how to reason out!

 

[epenguin]

a and b seem to me OK.

Dumas, Dumas, it rang a bell. I'm sure we did something, calculations, maybe experiments and calculations at school, so I now look up what it was, there is some practically washed out memories somewhere there.*

Anyway the Wiki description says "The vessel is then heated in a boiling water bath; all the air within the flask would be expelled, replaced by the vapor of the unknown substance" and then the flask is a sealed. So that appears to me quite a clue - does that suggest to you how to reason out, and if you have any doubts what are they? You are unfortunately not doing the experiment, but imagine you are doing it, and thinking of what purpose you’re doing it for.

*" culture is what remains when you have forgotten everything you ever learned"