Question: Why do some liquids need to be colder to freeze?

Shreesha Bhat answered on 17 Mar 2015:

Depends on the freezing and boiling point of the liquids and the composition of the liquid. Like for example, if you have salt or sugar in a liquid, it will freeze at much lower temperatures than normal, because the entropy involved with sugars/ salts are more, and it doesnt let the water molecules pack into solid ice so easily. You need more lower temperatures to freeze these kind of liquids.

I can also give a completely different example. That is of liquid Nitrogen. Now, nitrogen is in gaseous form at room temperature, but at extremely low temperature, can be liquefied to liquid nitrogen! (around minus 175 to minus 190 degree C) And it freezes at minus 210 degree C. So, in this case, as the gas itself turns into a liquid at such low temperature, its freezing requires even lower temperatures!