What keeps ice from melting?

Question

Ok this is a gr7 question. We are creating "ice devices". I have to create a device that will keep ice from melting. I have no clue on what to do. Although I will most likely put the ice cube in a shoe box and wrap the ice in aluminum and maybe sprinkle some salt over it. Any ideas on how I should create this "ice device"??

By the way, again, this is a gr7 question. So I cant use all this "scientific" stuff. So try and keep it simple!!

Answer 1

Hi Jane, you want to surround the ice in a material that does not conduct heat very well such as household insulation like the first person mentioned. However, you also want to use a material that does not adsorb water or allow water to pass through the material because water can conduct heat very well. If it permeates through your box, heat will transfer through the wet material to your ice. On the outside of your box you can use aluminum foil. The foil will reflect radiant energy from the outside and reduce the amount of heat being conducted into your box.

So to keep it simple...

Make a box with a plastic bag inside in which you can put your ice in. Make sure to seal the bag tightly once the ice is inside the bag. The plastic bag will hold your ice and keep any water that forms from getting into the insulation. Next take household insulation that you can get at Home depot. Use the same thickness on each side of the box. The more you use the less heat transfer you will have. However, the more it will cost. Use as much as your budget allows. Next cover the outside of the box with aluminum foil.

Whatever you do, do not put salt or any other material that can dissolve in water on your ice! When you add two materials that can mix together that causes a freezing point depression which makes the mixture freeze at a lower temperature than either one does in the pure form.

This is why they put salt on the street - to cause the ice to melt by forming a mixture of ice and salt which makes salt water.

Answer 2

You have some good answers already. A few more suggestions... If you add salt to ice, the salt causes the ice to melt because, even if the ice does not loose any heat, the salt creates a lower melting point solution. You can take advantage of this because the action of salt and ice consumes heat. So... if you have a small piece of ice you want to keep frozen, place it inside a well sealed container and surround that container with a mixture of ice and salt. Even tho the ice in with the salt is melting, it's temperature is less than 0 degrees C so the piece of ice inside the small container will not melt. You need to be sure to keep the salt out of the small container and the whole device will last longer if the big container is well insulated. You could also use dry ice (frozen CO2) or you could create a refrigerator.

good luck

Answer 3

it's colour. it is white,this means as the sun's rays reach the ice they reflect back into space. This happened with the ice age,it lasted for thousands of years because of this matter,but what caused it to melt are volcanoes as they release a variety of gasses into the atmosphere,the most abundant being carbon dioxide which acts like a blanket on the earth,trapping in heat from the sun,which in turn started to melt the ice.
also the temperature keeps the ice from melting,it has to be below minus for it to remain this state,and any higher then the ice will start to melt. However salt will melt the ice as it contains various chemicals that the ice can not withstand such as sodium. The aluminium will keep the ice cool,because metal is a good conductor with the cold if there is a source to keep it cold,in this case the ice itself. the show box would work more efficiently if it is white,Because is it is black it would absorb the heat and act as an insulator which will melt the ice.

Answer 4

wool felt aluminum and newspaper all work if u ever need to keep your drink nice and cool on hot summer days such as july fourth or june 23 which is my birthday from kobe wright. By the way im better than kobe b. michael jordan and lebron james

Answer 5

Build a box with at least 18 cubic feet of space in it. Insulate each side with at leat 12 inches of R-60 insulation material, preferably with a vacuum containment barrier. Place heat pump cooling coils in the interior of the box, heat pump should be capable of at least 40,000 watts. Coat your ice cube in dry ice and place inside the box.

Answer 6

Hope this helps!

Answer 7

cold temperatures