# Which is colder, dry ice subliming at -78.5"^oF or ethyl alcohol freezing at -179"^oF?

Well the freezing point of $\text{ethyl alcohol}$ is $- 114$ ""^@C....
And the sublimation point of $\text{carbon dioxide}$ is $- 78.5$ ""^@C....
And thus $\text{ethyl alcohol}$ melts at a lower temperature than that at which dry ice sublimes............I can't help you too much with temperatures that use the $\text{Fahrenheit scale}$.