Vodka will not freeze if you put it in the freezer.

Vodka is a neutral spirit that contains only water and alcohol. It does not require refrigeration and can be stored at room temperature for years (but why?). The freezing point of alcohol is at -113 Celsius so unless you have an industrial freezer, the vodka will remain nice and cold albeit a bit thicker in consistency. It also tastes better chilled as the freezing temperature numbs your taste buds during entry and you feel less of the alcohol 'burn' which makes chilled/frozen vodka so popular as shots.

The vodka (or most varieties of hard liquor, for that matter) will still get just as cold as anything else that is stored in the same freezer, it just won’t freeze. This is because while water solidifies at 32ºF, the ethanol alcohol found in potent potables has a freezing point of -173ºF!

This means that the freezing points of various liquors depend on the percentage of alcohol they contain, which we call a liquor’s ‘proof’ (you’ve seen the word on some bottles). Lower proofs translate to higher freezing points because those varieties contain a higher ratio of water to alcohol, and vice-versa.