I want to create a steam bath for a reaction the proceeds well at 105℃. I cannot use pure (demineralized, anyway) water for this, since it would boil at 100℃ at STP.
As such I figured that maybe I could get the required temperature by mixing water with another liquid (with which water is miscible) which has a higher boiling point (e.g. vinegar at BP around 118.5℃ or vegetable glycerin with BP at 190℃).
Does the boiling point of the mixture of liquids proceed in a linear manner between the two temperatures? E.G. would a volume of 50% water & 50% VG boil at 145℃?
As it is being done right on the boiling point of the combined liquids, I expect to lose some of the liquid to steam and need to add more. Will the lower temperature liquid boil out first?