Q. Why is salt sprinkled on the snow on the roads?
Ans. Salt, when added to water, lowers its freezing point. Generally snow is formed as water crystals when the temperature of water reaches 0o C. When Na+ and Cl− ions of the salt get in the way of the water molecules, it makes it difficult for them to rearrange into crystals. Thus, the salt solution remains in a liquid state for longer time as compared to plain water. In this way, salt sprinkled on the snow covered roads lowers the freezing point of water which prevents the formation of fresh snow thereby effectively reducing the amount of snow already present.