People have proposed towing icebergs to arid parts of the earth as a way to deliver freshwater. Explain why icebergs do not contain salts although they are formed by the freezing of ocean water (i.e saltwater)
It's the water that freezes, not the salt. In fact, many compounds are prepared in pure form by freezing them out of solution.
Icebergs are massive chunks of ice that break off from glaciers or ice shelves and float on the ocean's surface. Although they form from freezing seawater, icebergs are composed of freshwater and do not contain salts. This is due to the process of how icebergs are formed.
When seawater freezes, the process begins by forming pure ice crystals. As the freezing progresses, the ice crystals start to push away the dissolved salts and impurities, leaving them behind in the unfrozen seawater. The pure ice crystals continue to grow, incorporating only freshwater molecules from the remaining liquid.
As a result, when the freezing is complete and an iceberg is formed, it consists almost entirely of fresh water. The expelled salts are left in the surrounding seawater, which is more saline compared to the freshwater iceberg. It's worth noting that the expelled salts can contribute to increased salinity in the surrounding seawater, which may affect marine life and ecosystems.
To further explain, the freezing process is a physical separation of the water molecules from the dissolved salts. When water freezes, the water molecules arrange themselves in a crystal lattice structure, forming a solid ice structure. During this process, the pure water molecules are held in place within the ice lattice, leaving behind most of the salts and impurities.
If you are interested in understanding the science behind this process, you can explore the topic of phase transitions and the properties of water. It's fascinating to learn how the arrangement of water molecules changes as they transition from a liquid state to a solid state.