Most everyone is familiar with applying salt to the roads during winter to melt ice. I'm wondering if there's anything special about placing salt on the roads or would any other substance, sand for example, work equally well in melting the ice.
Yes, applying salt to melt ice it is special:
- Salt is a great ice melter because it causes “freezing point depression.” This means that salt helps in lowering the freezing point and, consequently, the melting point of water (the main component of snow and ice). In its pure state, water freezes at 0°C or 32°F. By using salt, that temperature can be lowered, which forces the ice to melt and prevents the water from freezing or re-freezing. This does not happen with sand.
- After melting, no additional effort is needed to clean the roads, because salt mixes with water. If you use sand, additional work will be needed to remove it from the streets afterwards.
- Salt is much cheaper than other chemicals, although arguably more expensive than sand, depending on location.
Salt is recyclable, so no wastage or decompositon of salt is there in such process.Since salt becomes soluted in the melted ice, it gets washed away and absorbed by the ground. This makes salt hard to retrieve after use, and harms the environment by damaging the plants in the area.