Thread: Salt

Sooo...

I read salt was precious in old times because it preserved food so well.

Also salt kills snails superfast because it... drains them of water?

We use salt in food for some reason (The taste? Hard to believe)

Salt is in the ocean (duh) and if you drink saltwater you dehydrate to death. (How can a tiny amount of salt in the water - outhydrate so much water?)

I also read that you can use salt+water in beer/soda to lower the temperature really fast to make it cooler.

Now. What Im really wondering is how such a simple thing like salt can have such a strong effect, and such a variety of uses in so many areas. Why is salt so special?

Salt isn't really that special.

There are all sorts of chemicals we need in quite tiny amounts to stay healthy. The amount of Vitamin C you need to stay free of scurvy is also tiny, as are the amounts of Vitamin D, magnesium, phosphorus and calcium to avoid rickets. The amount of iodine we need to keep our thyroids healthy is far, far less than the salt we need to keep our metabolism balanced in other ways.

Come to think of it, looking at those minerals whose shortage can lead to rickets, that might also add to the attraction in older societies for salt - because they didn't refine it much and it would have been an assembly of various salts as well as simple Na Cl. If having salt in your diet literally stopped children from getting rickets, that would be an additional attraction.

As for dehydration and other preserves. Yes, it's pretty good.

For dehydrating snails and people, it's all a question of balance. Too much will kill you.

temperature has no effect with respects to soluble rate therefore

It has the same effects as most other salts, but this one is none toxic and very common.

CaCO3, is similar, but it can bubble, and might leave calcium residue.

KCl, also similar, but NaCl is waaaaay more common.

NH4NO3 is also similar, but organic, and not inert.

Mg can also substitute for Na, but much less common.

Think of salt, as an iron ingot. It'll be used forever, but the actual use it'll get, is limited due to it's availability. If we had infinite amounts of iron, and it would not cost energy to smelt or form, all our homes would be solid steel/iron. Just a thought..

Originally Posted by Raziell

Sooo...

I read salt was precious in old times because it preserved food so well.

Also salt kills snails superfast because it... drains them of water?

We use salt in food for some reason (The taste? Hard to believe)

Salt is in the ocean (duh) and if you drink saltwater you dehydrate to death. (How can a tiny amount of salt in the water - outhydrate so much water?)

I also read that you can use salt+water in beer/soda to lower the temperature really fast to make it cooler.

Now. What Im really wondering is how such a simple thing like salt can have such a strong effect, and such a variety of uses in so many areas. Why is salt so special?

Salt is dangerous to drink because it increases the concentration of salt in your body and the water in your cells moves out of the cells to the lower concentration of water outside. This causes your body to lose more water than it takes in and your kidneys will shut down from trying to filter too much salt. If you ever look at a red blood cell under a microscope in a salinous solution, the cells will shrivel up. Contrarily, they will explode in a solution of pure water. Pretty cool stuff.

Salt does not directly cool down soda faster. What it does is lower the freezing point of water so that the water itself can get below 0C without freezing. The liquid water with salt will actually be colder than ice without added salt. NaCl dissolves into Na+ and Cl- ions in water and allows it to stay liquid at lower temps. It's also the reason salt melts ice. It doesn't heat the ice, it just lowers the freezing point. So if your driveway is icy and it is 30 degrees F outside, salt could lower the freezing point to 29 F and the water is now no longer cold enough to stay frozen.

As an avid cook, I would argue that salt is essential in the vast majority of my cooking. Salt and pepper not only function as flavor, but salt has a very real chemical purpose in cooking. For instance, when sweating onions you should ALWAYS use salt. The salt draws out moisture and sweats the onion properly. I always use salt on steak as well because it pulls water to the surface of the meat and makes the sear stronger.

I think NaCl is a fascinating little molecule.

Originally Posted by martin123

temperature has no effect with respects to soluble rate therefore

It does have an effect, although it is quite small. But you can definitely dissolve more salt in hot water.

Originally Posted by Strange

Originally Posted by martin123

temperature has no effect with respects to soluble rate therefore

It does have an effect, although it is quite small. But you can definitely dissolve more salt in hot water.

This.

Temperature change is a factor in creating a supersaturated solution. You can increase solubility by raising the temperature, then dissolve more salt and lower the temperature again. Even a slight disturbance will cause the solution to precipitate out the excess salt. It's a pretty good experiment when you're trying to get your 9 year old cousin interested in science.

Instead of NaCl, you could have used any other inert, nontoxic, and "highly soluble in water" kind of salt.

Sure, but everyone knows what NaCl is.

When you take something they eat every day and explain that if you break it apart, into pure sodium metal and diatomic chlorine, they would either be blown up or poisoned....well, it tends to get their attention.

Salt also attract water very strongly. If you put a bottle of (dry) salt in a damp environment: the bottle will be filled with (salty) water after some time!