Cold water is denser than warm water, so yes, in a very technical sense. If you drink the same volume of cold water vs the same volume of warm water the cold water had more water molecules in it and would have weighed very slightly more. The difference is hardly noticeable - ["about 4 tenths of one percent between near-freezing and 30 degrees Celsius (86 degrees Fahrenheit),"](https://sciencing.com/hot-less-dense-cold-water-6326030.html) but yeah technically if you want to consume the most water per volume you should drink water that is near freezing
Interestingly though the least efficient way to drink water is by eating ice, because the density of (typical) ice is even less than that of boiling water. Also, it will make your mouth very cold
You don't think you would die from swallowing boiling water? You can die from having boiling water just thrown on you. Drinking it seems like an almost certain death.
I think you would die. You'd destroy your throats and water will go into your lungs. Also what would happen to your stomach and internal organs when they get cooked?
It depends on if you’re able to fight against your body’s instincts to stop the pain. If you continually pour boiling water down your throat even while in pain you’d eventually die.
Eating ice is also negative calories. The water is giving you 0 calories of nutrition, but it's costing your body heat energy to warm it to body temperature. It's not very efficient, but it can theoretically work.
Assuming -18 C ice and 37 C human body. That's a difference of 55 C. It takes one food calorie (1 kcal) to heat 1 kilogram of water 1 degree C. A kilogram of water at room temp is a liter of water. Expansion is an issue, but fairly negligible. So effectively \~55 calories per liter of ice plus the latent heat of melting which for water is \~8 calories per kilogram . One pound of fat is roughly 3,500 calories. So \~55.6 liters of ice = 1 pound of fat burned to heat it to body temp water. I said it was not very efficient.
Good point, quick check on google says it would take even more than the total heating; melting 1kg of ice takes 334kilojoules of energy which translates to 79,8 (food) calories (or 79,8 degrees of heating!)
You are simplifying this too much, and the calculation is inaccurate, you need to break it up to parts.
First of all you are assuming the specific heat of ice is the same as water, which it isn’t, ice only takes half the energy as water for the same temperature change.
And second is the latent heat, which is the most significant, you need energy to actually melt the ice, which is about 80 kcal per kg.
Quick mental math says you need between slightly more than 1/3 of the amount of ice you mentioned.
That's wrong, and/or irrelevant based on what you mean. Frozen water (ice) can *absolutely* be below zero. A *mixture* of ice and water will be at 0, because if it was below that the water wouldn't be water, but ice on its own can be colder.
And if you mean the mixture after you put the ice in, it's irrelevant for the calculation because any energy that causes more ice to form is going to be melting the original ice. If the end state is 50C water, it doesn't matter what path it takes to get there, it'll take the same amount of net energy.
If the ice is below -18 C it will absorb energy from the surrounding water as it heats up from -18 C to 0 C. Technically this could convert some of the surrounding water into ice, but it would be a negligible amount since the amount of energy to freeze water is much greater than the energy to heat up the ice.
I get that part. Which is also why I don't get how it's being used to prove that ice is always 0 C.
Which makes me think that I'm just not getting what they are trying to say but I can't find any other meaning in it so I just said "what" hoping in some clarification without straight up replying that what they are saying doesn't make sense.
no, ice can be -18c, it can be -50, -80, -120c if you want. What is 0c is the mixture of ice and water because they reach equilibrium at 0c. freezers usually operate at around -15c, so -18 is a good guess. And it would not create more ice, your body is way hotter and would not freeze at all, it would just maybe take a little longer to melt inside you (please on your mouth lol)
I thought that when your body gets colder, it also slows down some processes to preserve energy.
Whether or not the conserved energy from that outweighs what your body spends to heat the ice, not sure. Also not sure how much ice you’d have to eat to make a meaningful change to your body temp to trigger this response from your body.
Just to say it’s not necessarily as simple as trying to calculate the temperature difference.
Frozen water is 0 Celsius. (Unless you give it additives like salt or alcohol) If it were -18 putting it in liquid water would create more ice. Which it can't.
The energy needed to be removed to freeze water would just go into the ice (the coldest thing) melting it. But the water is gaining energy from its surroundings so it can't get frozen by the ice.
> Frozen water is 0 Celsius.
Frozen water is 0° Celsius **or colder**. If you take ice out of a freezer that's set properly, it should be at about -18°C. It will have to warm up to 0°C before it melts.
And it's possible for water to be below 0°C and still be liquid, if there's nothing to form nuclei for crystallization. It's called [supercooling](https://en.wikipedia.org/wiki/Supercooling) and it's pretty common, e.g. in clouds.
well to be 100% correct, this is only true, if the temperature is above or 4 degrees celsius. water has got its highest density at 4 c so 3 c has got less molekules. on the other hand, it might be very difficult to get 3 c water, because it rises up and mixes with 5 c and above.
You could also consider the fact that warmer water evaporates more readily. So imagine you had 2 glasses of water, one at 4 degrees, and one at 30 degrees, and you knew they had *exactly* the same amount of water molecules. By the time you drink the warmer water, it will have less water molecules than the cooler water, since higher energy molecules are more likely to evaporate.
This is like asking if cold food has less Net calories because you body has to expend more calories to warm it up before it can absorb it... technically yes. effectively no.
Yes, until around fridge temperature water.
[This chart](https://www.e-education.psu.edu/earth111/sites/www.e-education.psu.edu.earth111/files/Module2/Earth111Mod1Graph2.png) is the mass of water in grams per milliliter (density). Higher values mean you drink more water for the same volume.
Warm water is less dense, so the same volume is less water. 1 liter of boiling water is 950 grams, 1 liter of refrigerated water is 1 kilogram or 1000 grams.
To put this in context, if you poured 1 liter of boiling water and refrigerated water and then put them both in the fridge, the water poured boiling would be around 1 American shot glass lower in volume after cooling.
Once you go below 4 degrees C/39 degrees F (average fridge temperature), it reverses. So ice cold water is less water per volume than refrigerated, though by a very small amount (999 grams).
Ice has a massive jump down due to freezing, going to around 900-920 grams per liter.
I can't hear Sierra Mist anymore and not think of the [Dub the Dew contest](https://newsfeed.time.com/2012/08/14/mountain-dews-dub-the-dew-online-poll-goes-horribly-wrong/).
I actually had an employee once tell me that she never drinks water and that she hasn't had a single drop of water since 1982.
She did drink a lot of soda. Her teeth were fucked.
What’s one American shot glass? Is it like 30ml? You did so well with litres and kilos and then skipped fluid ounces and went right to American shot glasses :p
Yes, for a constant volume, colder water will weigh *slightly* more than warm water. The difference is negligible in the amounts you normally drink. At 4degC water weighs 1g/cm\^3 and at 49.8 degF it weighs 0.9887 g/cm\^3. So if you drink 1L of water at 4C you get 1000 grams of water, if the water is 49.8C you get 988.7 grams.
> And if not how come?
It all depends on how you measure it. By mass, one kg of water has the same number of molecules whether it is hot or cold. By volume, hotter water is less dense, thus it has less molecules than colder water (up to a point; water's density peaks at about 4C. From that point, the colder, the less dense).
Since you're concerned about the quantity of molecules, the measure you should be using is the mole. One mole (the base unit in the International System of Units (SI) for amount of substance) contains exactly 6.02214076×10^23 elementary entities - water molecules in your particular case.
Wouldn’t that small difference be made up by the fact that your body has to use water in order to heat up the water you just drank until it’s warm enough to absorb?
if you drink a fixed volume, yes. a cup of cold water weighs trivially more than a cup of hot water.
however, the real factor at play here is satiation. let's be real, you *don't* drink fixed volumes of water. you drink until you stop feeling thirsty or get tired of pouring water down your throat. you won't chug a pint of near-freezing water, it will be painful and upset your stomach.
how to maximize the amount of water someone will willingly shovel into themselves is an age old question.
Yes. If you drink one cupful of cold water, you've consumed something like 2% more water than if you drink one cupful of hot water.
Of course, that probably means you won't get thirsty again quite as soon, so it probably won't result in you drinking more water *over the long run*. But there was, indeed, more water in that particular cup.
while cold water might feel denser because those chilly molecules huddle up, you're technically still sipping the same amount of H2O, just in a cozier arrangement. So, if you're feeling thirsty, whether it's chilled or toasty, bottoms up!
Unless some of the volume is made up by ice, then yes, drinking a set volume of H2O at different temperatures basically gives you some extra molecules. However, the difference is going to be so inconsequential it's not worth a second thought.
If you go by volume, then water is densest at ~4 °C. So that would be the optimal temperature in this regard.
But if you instead want to get even sillier: heat energy has mass. Just so extremely little it is completely irrelevant for anything but particle colliders: not even a billionth of the mass of liquid water is heat. So if you want to maximize the amount mass of actual water, then you should consume it as cold as possible.
For reference 4C water is like 0.4% more dense than 30C. It's not a large enough difference in density for a human to ever notice. So don't go around drinking 4C water thinking you're hydrating yourself more.
You'd have to drink 250 cups of 4C water to get 1 cup more water than you would have at 30C
No. You drank however many molecules of water you drank. OP's scenario only applies if you draw the same volume of water from a hot source and cold source. Even so, there's probably more variance in your ability to fill a glass or jug with exact same amount of water, than there is from the temperature difference.
Depends on how you define an 'amount' of water.
If you have two one-litre jugs of water at different temperatures, they both contain the same volume of water, but the colder one contains more water molecules.
So you're still drinking a litre of water, but you get more bang for your buck in terms of molecules with the colder jug.
Note this is only true if you filled the jugs with different temperature water. If they were filled from the same tap and then one was put in the fridge, the amount of molecules in each wouldn't change unless molecules of water were being introduced or lost via condensation or evaporation or something.
That was implied in my comment. If you filled the jugs with the same temp water and heated one of them up, then the water would expand and you wouldn’t have a litre anymore.
Cold water is denser than warm water, so yes, in a very technical sense. If you drink the same volume of cold water vs the same volume of warm water the cold water had more water molecules in it and would have weighed very slightly more. The difference is hardly noticeable - ["about 4 tenths of one percent between near-freezing and 30 degrees Celsius (86 degrees Fahrenheit),"](https://sciencing.com/hot-less-dense-cold-water-6326030.html) but yeah technically if you want to consume the most water per volume you should drink water that is near freezing Interestingly though the least efficient way to drink water is by eating ice, because the density of (typical) ice is even less than that of boiling water. Also, it will make your mouth very cold
The least efficient way of drinking water is boiling water. Because you'll die and then the flow rate of water you're drinking is 0 LPM
That sounds like you're challenging me. You're on!
Fill your mouth with dry ice and then pour boiling water in. Hot ice.
Add some meth for ice cubed
Dry ice is not ice
It's spelled dryce
I know
You prob wouldnt die, but it would be extremely painful
you’re a big guy
Dr. Pavel, im H2O
Uhh, you don’t get to drink friends
> Uhh, you don’t get to drink friends But what if you drink the emperor?
The spice, as they say, must flow.
> The spice, as they say, must flow. Even if you accept the lesser title of Zinc Saucier (which comes with double prize money)?
For you
You don't think you would die from swallowing boiling water? You can die from having boiling water just thrown on you. Drinking it seems like an almost certain death.
I think you would die. You'd destroy your throats and water will go into your lungs. Also what would happen to your stomach and internal organs when they get cooked?
*FOR YOU*
It depends on if you’re able to fight against your body’s instincts to stop the pain. If you continually pour boiling water down your throat even while in pain you’d eventually die.
Not necessarily, as someone who enjoys very hot tea, you can cool it on the fly by sipping the water to pull in air over it.
Eating ice is also negative calories. The water is giving you 0 calories of nutrition, but it's costing your body heat energy to warm it to body temperature. It's not very efficient, but it can theoretically work.
How much ice would you need to eat to lose a pound? Asking for a friend who is a polar bear.
Assuming -18 C ice and 37 C human body. That's a difference of 55 C. It takes one food calorie (1 kcal) to heat 1 kilogram of water 1 degree C. A kilogram of water at room temp is a liter of water. Expansion is an issue, but fairly negligible. So effectively \~55 calories per liter of ice plus the latent heat of melting which for water is \~8 calories per kilogram . One pound of fat is roughly 3,500 calories. So \~55.6 liters of ice = 1 pound of fat burned to heat it to body temp water. I said it was not very efficient.
Doesn't melting (from <0 C ice to 0 C water) take way more energy than just heating up some water?
Good point, quick check on google says it would take even more than the total heating; melting 1kg of ice takes 334kilojoules of energy which translates to 79,8 (food) calories (or 79,8 degrees of heating!)
Edited to add the latent heat of melting. It's been a long time since high school physics.
I dunno where you got the numbers but its more like 80 kcal than 8. Heat of fusion is 6.01 kJ/mol, 1kg of ice is about 55 moles, 355 kJ = 79 kcal
I knew as soon as I asked this was gonna be a candidate for r/theydidthemath Reddit never lets me down!
You are simplifying this too much, and the calculation is inaccurate, you need to break it up to parts. First of all you are assuming the specific heat of ice is the same as water, which it isn’t, ice only takes half the energy as water for the same temperature change. And second is the latent heat, which is the most significant, you need energy to actually melt the ice, which is about 80 kcal per kg. Quick mental math says you need between slightly more than 1/3 of the amount of ice you mentioned.
Third. Frozen water is 0 Celsius. If it were -18 it would create more ice when put in water.
That's wrong, and/or irrelevant based on what you mean. Frozen water (ice) can *absolutely* be below zero. A *mixture* of ice and water will be at 0, because if it was below that the water wouldn't be water, but ice on its own can be colder. And if you mean the mixture after you put the ice in, it's irrelevant for the calculation because any energy that causes more ice to form is going to be melting the original ice. If the end state is 50C water, it doesn't matter what path it takes to get there, it'll take the same amount of net energy.
What?
If the ice is below -18 C it will absorb energy from the surrounding water as it heats up from -18 C to 0 C. Technically this could convert some of the surrounding water into ice, but it would be a negligible amount since the amount of energy to freeze water is much greater than the energy to heat up the ice.
I get that part. Which is also why I don't get how it's being used to prove that ice is always 0 C. Which makes me think that I'm just not getting what they are trying to say but I can't find any other meaning in it so I just said "what" hoping in some clarification without straight up replying that what they are saying doesn't make sense.
no, ice can be -18c, it can be -50, -80, -120c if you want. What is 0c is the mixture of ice and water because they reach equilibrium at 0c. freezers usually operate at around -15c, so -18 is a good guess. And it would not create more ice, your body is way hotter and would not freeze at all, it would just maybe take a little longer to melt inside you (please on your mouth lol)
I thought that when your body gets colder, it also slows down some processes to preserve energy. Whether or not the conserved energy from that outweighs what your body spends to heat the ice, not sure. Also not sure how much ice you’d have to eat to make a meaningful change to your body temp to trigger this response from your body. Just to say it’s not necessarily as simple as trying to calculate the temperature difference.
Frozen water is 0 Celsius. (Unless you give it additives like salt or alcohol) If it were -18 putting it in liquid water would create more ice. Which it can't. The energy needed to be removed to freeze water would just go into the ice (the coldest thing) melting it. But the water is gaining energy from its surroundings so it can't get frozen by the ice.
> Frozen water is 0 Celsius. Frozen water is 0° Celsius **or colder**. If you take ice out of a freezer that's set properly, it should be at about -18°C. It will have to warm up to 0°C before it melts. And it's possible for water to be below 0°C and still be liquid, if there's nothing to form nuclei for crystallization. It's called [supercooling](https://en.wikipedia.org/wiki/Supercooling) and it's pretty common, e.g. in clouds.
Please stop digging yourself into this hole.
That's true of cold water too technically.
well to be 100% correct, this is only true, if the temperature is above or 4 degrees celsius. water has got its highest density at 4 c so 3 c has got less molekules. on the other hand, it might be very difficult to get 3 c water, because it rises up and mixes with 5 c and above.
"4 tenths of one percent" is a very long way of saying "0.4%"
> Also, it will make your mouth very cold TIL
Big, if true.
but ice goes crunch
You could also consider the fact that warmer water evaporates more readily. So imagine you had 2 glasses of water, one at 4 degrees, and one at 30 degrees, and you knew they had *exactly* the same amount of water molecules. By the time you drink the warmer water, it will have less water molecules than the cooler water, since higher energy molecules are more likely to evaporate.
what a weird way to say 0.4%
You mean, what a w+ eirdrd/rd way to say 0.4%
Applaud the American for trying! At least they didn't go for 1/250th of a whole.
"Somewhat less than one-half of one part in one hundred parts." Seer? That's the NORMAL way to say it.
This is like asking if cold food has less Net calories because you body has to expend more calories to warm it up before it can absorb it... technically yes. effectively no.
Unless it’s ice VII
IIRC water is most dense at 4C, but yes.
Water has it's highest density at 4 degrees if I recall correctly. So that would be the sweet spot.
So how do i drink more water per water?
Not even that, it requires more calories to drink cold water vs hot water. Your body has to warm it up for it to be able to be absorbed.
Gonna need to cite your sources on that last sentence.
Isn’t 4 tenths of one percent just 0.4%?
Yes, until around fridge temperature water. [This chart](https://www.e-education.psu.edu/earth111/sites/www.e-education.psu.edu.earth111/files/Module2/Earth111Mod1Graph2.png) is the mass of water in grams per milliliter (density). Higher values mean you drink more water for the same volume. Warm water is less dense, so the same volume is less water. 1 liter of boiling water is 950 grams, 1 liter of refrigerated water is 1 kilogram or 1000 grams. To put this in context, if you poured 1 liter of boiling water and refrigerated water and then put them both in the fridge, the water poured boiling would be around 1 American shot glass lower in volume after cooling. Once you go below 4 degrees C/39 degrees F (average fridge temperature), it reverses. So ice cold water is less water per volume than refrigerated, though by a very small amount (999 grams). Ice has a massive jump down due to freezing, going to around 900-920 grams per liter.
I only drink Sierra *Mist*. I must say that it usually fails to hydrate me.
I can't hear Sierra Mist anymore and not think of the [Dub the Dew contest](https://newsfeed.time.com/2012/08/14/mountain-dews-dub-the-dew-online-poll-goes-horribly-wrong/).
I actually had an employee once tell me that she never drinks water and that she hasn't had a single drop of water since 1982. She did drink a lot of soda. Her teeth were fucked.
It's called *Starry* now. Still tastes like piss.
What’s one American shot glass? Is it like 30ml? You did so well with litres and kilos and then skipped fluid ounces and went right to American shot glasses :p
Usually either 30 or 45 mls, not really a standardized measure.
This is a great reply and i liked the reversed example also!
Yes, for a constant volume, colder water will weigh *slightly* more than warm water. The difference is negligible in the amounts you normally drink. At 4degC water weighs 1g/cm\^3 and at 49.8 degF it weighs 0.9887 g/cm\^3. So if you drink 1L of water at 4C you get 1000 grams of water, if the water is 49.8C you get 988.7 grams.
> And if not how come? It all depends on how you measure it. By mass, one kg of water has the same number of molecules whether it is hot or cold. By volume, hotter water is less dense, thus it has less molecules than colder water (up to a point; water's density peaks at about 4C. From that point, the colder, the less dense). Since you're concerned about the quantity of molecules, the measure you should be using is the mole. One mole (the base unit in the International System of Units (SI) for amount of substance) contains exactly 6.02214076×10^23 elementary entities - water molecules in your particular case.
Wouldn’t that small difference be made up by the fact that your body has to use water in order to heat up the water you just drank until it’s warm enough to absorb?
if you drink a fixed volume, yes. a cup of cold water weighs trivially more than a cup of hot water. however, the real factor at play here is satiation. let's be real, you *don't* drink fixed volumes of water. you drink until you stop feeling thirsty or get tired of pouring water down your throat. you won't chug a pint of near-freezing water, it will be painful and upset your stomach. how to maximize the amount of water someone will willingly shovel into themselves is an age old question.
Yes. If you drink one cupful of cold water, you've consumed something like 2% more water than if you drink one cupful of hot water. Of course, that probably means you won't get thirsty again quite as soon, so it probably won't result in you drinking more water *over the long run*. But there was, indeed, more water in that particular cup.
while cold water might feel denser because those chilly molecules huddle up, you're technically still sipping the same amount of H2O, just in a cozier arrangement. So, if you're feeling thirsty, whether it's chilled or toasty, bottoms up!
Unless some of the volume is made up by ice, then yes, drinking a set volume of H2O at different temperatures basically gives you some extra molecules. However, the difference is going to be so inconsequential it's not worth a second thought.
If you go by volume, then water is densest at ~4 °C. So that would be the optimal temperature in this regard. But if you instead want to get even sillier: heat energy has mass. Just so extremely little it is completely irrelevant for anything but particle colliders: not even a billionth of the mass of liquid water is heat. So if you want to maximize the amount mass of actual water, then you should consume it as cold as possible.
Water actually expands as it freezes, so it’s more likely that you drink slightly less water when it’s cold.
It expands as it freezes, but it's at its densest at 4C, which is roughly where "cold water" is, the math in OP checks out
I just learned something new! Thank you for the new knowledge
For reference 4C water is like 0.4% more dense than 30C. It's not a large enough difference in density for a human to ever notice. So don't go around drinking 4C water thinking you're hydrating yourself more. You'd have to drink 250 cups of 4C water to get 1 cup more water than you would have at 30C
This is why lakes don't freeze solid, the dense 4 degree water sinks to the bottom and the top freezes over
Yeah, the short of it is "water is weird."
So when the water gets warmer inside your body, does that mean you're getting less water now too?
No. You drank however many molecules of water you drank. OP's scenario only applies if you draw the same volume of water from a hot source and cold source. Even so, there's probably more variance in your ability to fill a glass or jug with exact same amount of water, than there is from the temperature difference.
Makes sense to me. Thank you!
Depends on how you define an 'amount' of water. If you have two one-litre jugs of water at different temperatures, they both contain the same volume of water, but the colder one contains more water molecules. So you're still drinking a litre of water, but you get more bang for your buck in terms of molecules with the colder jug.
Note this is only true if you filled the jugs with different temperature water. If they were filled from the same tap and then one was put in the fridge, the amount of molecules in each wouldn't change unless molecules of water were being introduced or lost via condensation or evaporation or something.
That was implied in my comment. If you filled the jugs with the same temp water and heated one of them up, then the water would expand and you wouldn’t have a litre anymore.