What temp does freon freeze at?

Refrigerant (freon) does not freeze, at least not at any temperatures one could comprehend let alone encounter here on earth. It is used in cooling/refrigeration systems for its favorable boiling temperatures. If that is what you are asking, the answer would depend on a few things, such as type of refrigerant and the temperature and pressure of the vessel containing it. Ill give an example using R-22 the most common refrigerant used for household cooling systems. At atmospheric pressure at sealevel (0psig/14.7psia). R-22 boils at -60*F, releasing liquid R-22 directly from its container would cool whatever surface it came into contact with to this temp and it would create a nasty burn type injury (frostbite) if that surface happens to be your skin. But, in a properly operating a/c system a typical low side pressure would be around 70psig, under this pressure the refrigerant boiling point is raised from from -60*F to +40*F, producing appx 50*F discharge air into the home. For a more detailed explanation see my answer to: How does air conditioning work? on this site.