I would like to embed a preparation frozen at -180°C in a liquid Ethane-methanol solution in frozen methanol. For this I first want to make a mix of liquid ethane and methanol in a ratio of 20 to 1 at a temperature of -89 degrees Celsius and then cool it down again to -180. At this temperature, both substances are liquid. I do get some methanol dissolved but not all of it. It takes about 2 hours to get just 0.2ml dissolved in 9ml liquid ethane. Could it be that the substances just don’t want to mix? or is the low temperature playing tricks on me?
I start with 9ml of liquid ethane, adding 0.5ml of methanol at -89 degrees Celsius at a temperature of -89 degrees Celsius. This is mixed with a stirring magnet and it is kept at temperature during stirring.
The goal is to vacuum the mix at the end. the ethane evaporates and the methanol remains frozen.
Answer
Hi Frank,
I obviously have no experience with cryogenic mixtures of ethane and methanol, but since this question has been open for a while, I’ll give it a try.
Methanol is one of the most polar organic solvents, so as a rule it is not miscible in all proportions with non-polar organic solvents, such as pentane. Furthermore, it is generally the case that the solubility increases with increasing temperature. You can try putting the mixture in an ultrasonic bath. In my experience, the resolution is much faster than that. Of course, if methanol is insoluble at that temperature, sonicating won’t help either.
Answered by
Dr Etienne Jooken
Chemistry
Old Market 13 3000 Leuven
https://www.kuleuven.be/
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