What liquid takes the longest to melt after being frozen?

[NoOneLt]

Hi everyone,

Please help, i need to find liquid or maybe something else witch can freeze in freezer overnight, or even longer, most important thing that this liquid would unfreeze as long as possible.

Or H2O the way to go?

Thank you!

 

[.Scott]

Hi everyone,

Please help, i need to find liquid or maybe something else witch can freeze in freezer overnight, or even longer, most important thing that this liquid would unfreeze as long as possible.

Or H2O the way to go?

Thank you!

I will take your question literally. If you want something to take as long as possible to melt, pick something with a high melting point. For example, Tungsten at 3422 degrees centigrade, will stay solid longer than any other metal. Or Gallium, liquid in your hand but will solidify at about 30 C.

So what exactly are you trying to do?

If you are looking to keep something cold, water has a high latent heat of fusion and is therefor very effective. See: https://en.wikipedia.org/wiki/Ice_pack.

 

[Borek]

If you want something to take as long as possible to melt, pick something with a high melting point.

And not with the highest possible enthalpy of fusion (which is just another way of pointing out how ambiguous the original question is )?

 

[NoOneLt]

Hey guys, sorry, plain simple, i use big bottle of water to cool down my room sometimes :) Maybe i could use something instead of water, something that will "melt" slower than water? Of course something that is possible to get easily and use indoors.

 

[.Scott]

I'm sure water is your best bet.
How hot is your room? How hot is it outside?

 

[berkeman]

And where is your freezer where you are making the ice in the first place? If it's in the same room, you're not really doing much overall cooling...

 

[NoOneLt]

Not in the same room of course :)

 

[.Scott]

Not in the same room of course :)

The reason I was asking additional questions is that I am not convinced you're basic technique is the best.
Of course, for most, they would install an air conditioner.
But there may be other methods. Can you cool air through evaporation and then direct it into your room? Instead of cooling your whole room, can you cool only the area where you work?

 

[NoOneLt]

AC would be the best option of course, but not possible, what i do is basically freeze ~2liters bottle of water and put it by the fan witch blows colder air where i need. Cheap and simple, not so effective maybe.

So if 2liter bottle of H2O melts in about 4 hrs a was just curious maybe something could keep up for 6 hours or so... Or i will just freeze 5 liters H2o :)

 

[Borek]

Water is the best thing here, high enthalpy of fusion, high specific heat, cheap, reusable. I don't think you will find something better (and not costing you an arm and a leg).

 

[NoOneLt]

Thank you!

 

[.Scott]

If you keep the fan on low, it will not generate as much heat and the ice will last longer.
Also, the "cool" may end up staying in the immediate area where you need it.

 

[rootone]

You could try slightly salted water which has a lower freezing point.
Not a lot lower but could add an hour or so before they need replacing.

 

[russ_watters]

AC would be the best option of course, but not possible, what i do is basically freeze ~2liters bottle of water and put it by the fan witch blows colder air where i need. Cheap and simple, not so effective maybe.

In the USA, air conditioners are rated in "tons", which comes from a time when people dug ice out of lakes and stored it for summer cooling. A typical window air conditioner has a rating of about 3/4 ton, which means it can provide as much cooling as melting 3/4 ton of ice per day. And you are trying to do the same thing with 2 liters of water a day. "not so effective" is the understatement of the month so far.

 

[stefan r]

Water is the best thing here, high enthalpy of fusion, high specific heat, cheap, reusable. I don't think you will find something better (and not costing you an arm and a leg).

By volume glass has more heat capacity. The heat of melt/freeze water is much more than the heat capacity. .

You can place bottle of grain alcohol in your bucket of water. That drives the temperature lower.

Length of time cooling is determined by the surface of your container. If it isolated or insulated the heat comes out slower.