Difference between revisions of "Chemistry of common things"

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and more importantly, the kidneys use water to dump what it collects.
 
and more importantly, the kidneys use water to dump what it collects.
  
It turns out that there is a maximum concentration of collected salt your kidneys can put into water you pee out,
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It turns out that there is a maximum concentration of collected salt your kidneys can put into water you pee out.
and it is lower than the concentration in seawater - roughly half.  
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Which means drinking water saltier than that, and your body is going to have to ''add'' water to get rid of said salt.
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The tipping point for this is well under the concentration in seawater - roughly half.  
  
 
Put another way, your kidneys can only make urine that is less salty than seawater, so you have to pee more water than you just drank.
 
Put another way, your kidneys can only make urine that is less salty than seawater, so you have to pee more water than you just drank.

Revision as of 20:17, 10 January 2022


Cooking

Doughs

See Doughs, batters, leaveners

Greenery

Trees, O2, CO2

Water

On hydration

Drinking slowly?

3 liters a day, or less?

Coffee

Alcohol

On bottled water

Demineralized and distilled water

Distilled water is nearly-pure H2O, because distillation means you move the water and leave behind most other things


Demineralized water means few to no minerals (fresh natural water has some, tapwater has a more-controlled bunch; see also hard water) by some method

...but says little about what else may still be in there
it's useful to keep minerals out of chothes irons, car batteries, and such (largely to avoid limescale)


On contents of demineralized water

Demineralized water often mentions it is not fit for consumption

in practice it's usually pretty clean water, but it's not guaranteed to be pure
largely because depending on the process of demineralization, there may be other things still left in there, say, a few bacteria. Your iron or car battery won't care, but you might
and because it doesn't matter for the intended uses
(also in part because it's also sold in supermarkets, so it's useful, possibly required, to point this out explicitly)


Does distilled or demineralized water lead to nutritional deficiency?

On water poisoning

This article/section is a stub — probably a pile of half-sorted notes, is not well-checked so may have incorrect bits. (Feel free to ignore, fix, or tell me)


Water poisoning happens when drinking a large amount in a short time, because of what it does to certain balances in your body, primarily salt and other electrolytes.


Drinking a lot of water means shifting various balances, basically diluting various things with water containing little else, and doing that enough causes effects like osmosis taking necessary salts out of your kidneys.

The body contains something like 0.15% salt in general, and blood 0.9%.

If you manage to dilute that significantly, it starts affecting cellular function in general. You will probably notice this via many of them, including headache, muscle control, possibly vomiting and diarrhea.

The fact that you will feel bad is why most people are at negligible risk.


Time is a significant factor,

in part because because it takes a while for you to absorb water you drink, basically while it's in your gut
(related tow why quick rehydration in hospitals is done via saline IVs, not just making you drink and waiting a few hours).
also in part because if it's not fast enough, your kidneys don't have too much trouble just making you pee a lot more. Which wastes some salt, but not very much(verify).

This is why you see statements like "3-4 liters within in a few hours".



Does distilled water do this a lot quicker?

No. The thing is that quickly drinking liters of almost anything will do this - anything other than precisely the concentration of things (primarily salt) inside your body.

So whether it's tap water, distilled water, coffee, or almost any other drink (other than maybe some specific sports drinks), it's going to dilute you.


Sure, tap water has things beyond H2O, including sodium. As does bottled water. The concentrations of these are very low (very roughly 0.003%(verify), aimed more at tasting like the water you're used to. For many thing it's not remotely the amount we need. For salt, it is primarily the salt we add to our food that helps us keep our salt balance, and your cravings will typically guide you to a decent amount of salt (actually, many of us eat a little too much salt).


Point is, the difference between that 0.003% in tap water and 0.000% in distilled water is basically negligible, because both are much lower than your body's 0.15% is.

While distilled is a little worse, the difference is negligible. Compared to how much you need, both are effectively zero.


If you're stranded in a desert for weeks, and have the choice of what water to take, maybe.

But even then it'd be a lot more important to catch the salt you sweat out.

And it might actually make a real difference what the non-distilled water is. If it's not regulated tap water, the possibility of pathogens may be a lot more important)


Water hardness

This article/section is a stub — probably a pile of half-sorted notes, is not well-checked so may have incorrect bits. (Feel free to ignore, fix, or tell me)

Fluoride in drinking water

Salty water

Resistance of water

See Electronics_notes/Resistors#Resistance_of_fluids

Oxyhydrogen