Question

How does adding salt affect the freezing point of water?

Answer 1

Where you're mixing two substances, you're making a whole new system and different from the original ones. The solution will have new properties, in function of the concentration. In terms of equilibrium, salt reduces pressure of steam in the solution increasing the boiling point, and decreasing the freezing point. The water-salt solution will freeze under 0°C and boil over 100°C