Salt, it seems like it’s the answer to everything.
– Sore Throat? Salt Water
– Icy Roads? Rock Salt
– Food Bland? Table Salt
– Dehydrated? Gatorade
– Tough Stains? Salt
– Chill Beverages Faster? Salt Water
– Spirits? Shot Gun (Salt Rounds)
There’s probably more uses.
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Salt is an ionic compound composed of a negative half (Cl-) and a positive charged half (NA+). Water is polar (water molecules also have negative and positive charged sides) so salt dissolves very well in water, and because it is an ionic compound, the Cl and Na halves dissociate and float around freely. This gives salty water some interesting properties.
For one thing, adding salt alters the freezing point of water slightly. The Na and Cl ions ‘get between’ the water molecules, so to speak, and prevent them from so readily forming a solid. This is why we spread rock salt on icy roads – the salt dissolves in the thin film of liquid water that is always present on ice, dropping its freezing point, which will in turn begin to melt the ice. This is also the property of salt water that you can take advantage of to chill a bottle of wine very quickly – it causes the ice to melt at a lower temperature, and lower-temperature icewater is better for chilling your drinks.
Some of the other useful properties of saltwater relate to the fact that saltwater has, uh, more salt in it than water that doesn’t. Let me explain. Solutions want to reach equilibrium with each other, even across very thin membranes. When a saltwater solution is brought into contact with a pure water solution, water molecules will move to the salty side. This exchange of molecules across such a membrane is called osmosis. Biology takes advantage of osmotic effects everywhere. So salt is a useful molecule to have in biology for water regulation, because salt concentrations can be used to draw water from one tissue to another. This is why salt is key for water regulation, and also why a saltwater gargle will soothe your throat – breaking up mucus (by drawing out water) and even drawing some water out of your throat tissues.
Finally, as alluded to above, Na+ ions have a positive electric charge, which all animal (and even some plants) life takes advantage of to create action potentials – essentially, electric charge imbalances in cell tissues. This is vital to the functioning of all muscle and nerve cells. So, the sodium component of NaCl is extremely vital for life. This probably explains why we find salt very tasty – in modern times, we can just put salt in everything, but for animals in the wild, it can be harder to come by salt. So we probably evolved to crave it a lil bit to induce us to take it in when it is available.
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