Answer to Question #320774 in General Chemistry for PooooOmp

Question

Salt is often used to melt ice and snow on roads in the winter and the temperature right now is -4.500°C. How much NaCl (complete dissociation) would be necessary to melt 1000kg of ice by bringing down the freezing temperature to -4.500°C?

Answer 1

When added to ice, salt first dissolves in the film of liquid water that is always present on the surface, thereby lowering its freezing point below the ices temperature. Ice in contact with salty water therefore melts, creating more liquid water, which dissolves more salt, thereby causing more ice to melt, and so on