# The difference between the freezing point of methanol and ethanol at different concentrations

I would like to ask a chemistry question: The freezing point of methanol aqueous solution between 0% and 90% is lower than that of ethanol aqueous solution; but why is the freezing point of ethanol aqueous solution between 90% and 100% lower than that of methanol aqueous solution?

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• You have not clarrified what percentages you are talking about. Is it by weight or volume? 2 days ago

The OP's claim that "The freezing point of methanol aqueous solution between 0% and 90% is lower than that of ethanol aqueous solution" is correct as data given in Engineering Tool Box (methanol/water) and Engineering Tool Box (ethanol/water): $$\begin{array}{c|c|c|c} \text{% MeOH (v/v) or (w/w)} & \text{The freezing point } (\pu{^\circ C}) & \text{% EtOH (v/v)} & \text{The freezing point } (\pu{^\circ C}) \\ \hline 0 & 0 & 0 & 0 \\ 13 \text{ or }10 & -7 & 10 &-4 \\ 24 \text{ or }20 & -18 & 20 & -9\\ 35 \text{ or }30 & -26 & 30 & -15\\ 46\text{ or }40 & -40 & 40 & -23\\ 56\text{ or }50 & -54 & 50 & -32\\ 66\text{ or }60 & -71 & 60 & -37\\ 75\text{ or }70 & -82 & 70 & -48\\ 83\text{ or }80 & -87 & 80 & -59\\ 92\text{ or }90 & -90 & 90 & -73\\ 100 & -98 & 100 & -115\\ \hline \end{array}$$
However the two last data points are simply the comparison of the freeing point of $$100\%$$ methanol and that of $$100\%$$ ethanol. Evidently, the freeing point of $$100\%$$ methanol is greater than the freeing point of $$100\%$$ ethanol (See Table of Melting points of alcohols). Thus, there is not an unusual reason for this change in trend.