Will dry ice freeze water?
Yes it will, since dry ice is colder than the melting point of water. Dry ice sublimes at -78.5 degrees C, and in doing so takes in very large amounts of energy from it’s surroundings, it would very easily and rapidly freeze water if you poured some on. The water will freeze at 0 degrees C, but it will rapidly cool down even more since the temperature difference between -78.5 C and 0 C is quite large. You can see a video here of dry ice skating around in shallow water: http://www.shawnlani.com/WORKS/ICY%20BOD… The reason it skates is because the water freezes around the dry ice very quickly, and the gas produced by the sublimating CO2 builds up underneath until it has enough pressure to break through some of the ice, this creates a jet of CO2 gas propelling it over the water. This is a similar principle to a dry ice bomb, where the pressure increase caused by the build up of gas is
