What mixing ratio of ethanol and acetone has the lowest freezing point? I am in the lab trying to make a sample for 1H NMR. It has to remain liquid at the lowest possible temperature.

I was recommended to use a mixture of ethanol and acetone because when they're mixed in the right proportions, the mixture has a very low freezing point.

I can not find this proportion anywhere. Does anyone know where to look for these things?

Here is a picture of what I'm looking for, but with ethanol and acetone instead of water - solvent:



PD:it's very likely that its methanol instead of ethanol, please let me know... I have access to both, I just want the one that will go to the lowest temp.
its me again, I  want to post the answer I found because I think it might be useful for somebody in the future; it appears a 2:3 molar acetone:methanol proportion gives the lowest freezing temperature ~158 K (see attached picture below).

It appears the difficulty finding these curves was because they are usually called "solid-liquid equilibrium" curves instead of "freezing point curves", as its the same physical situation (Explanation Here)

There is a large database of these in the following link.



EDIT: As commented by "Ivan Neretin", ethanol-acetone mixtures are also good for low freezing temperatures: