Will ice frozen at different temperatures (-20 degreees vs 20 degrees) melt at the same rate (72 degrees)?
342596
if you put -20 degree ice in the same room as 20 degree ice, the 20 degree ice will melt first. this is because the temperature of the -20 degree ice must first climb to 20, then to 32 where it starts to melt. the 20 degree ice has a head start, it just has to get to 32. there is no trick to this question, it follows common sense. the temperature of the colder ice will rise faster than the less cold ice, but it will always be colder until they both reach room temerature.
125319
The ice water will cool quicker.  The reason being, that the water will cover the entire surface area that you are trying to cool.  \n\nThat being said, it also won't last as long because it also has more surface area for the cooling to escape.
868477
water freezes at 32 degrees Fahrenheit, and 0 degrees Celsius\n\nthe colder the faster
1097232
Have you heard of boiling and freezing points. Each substance has a boiling and a freezing point there is a different one for each substance. The freezing point of H20 (hydrogen and oxygen) is 32 degrees Fahrenheit and the boiling point is 212 degrees Fahrenheit. Now these temperatures could be different if the water has anything else in it changing the molecular structure. Things like salt, calcium, ect. So in your bottle story....The gas (common air) which has things like helium, carbon and oxygen is on top and your water is on the bottom. This could get confusing but essentially when you shake it up you added other molecules into the water that have a lower or higher freezing point. Same idea as when you have a partially frozen bottle of water and you shake it up and it defrosts. It also has to do with the first law of thermodynamics...Energy can not be created or destroyed just transferred. So some molecules do not have enough energy to bond with one another but when you shake up the bottle it transfers energy allowing them to bond with one another. Hope I didn't confuse you too much.
874149
Yes.  Adding salt to frozen water lowers the melting point.  \n\nConsider that snow and ice are really the same thing, in different mass quantities - water in solid state due to ambient temperature.\n\nBest to you.
308984
I've actually tried this.  I put ice in a plastic bag and I also put some in a aliminum foil ball.  I came back 5 hours later and the ice in the plastic bag was melted but the foil ice was intact and partially whole.
8960
Depends on the air temp.... theres days where I have left ice fishing at night.. came back the next day and could poke a hole in the ice with my finger....\n\nIf your in an fish house and have it banked really well, the holes don't freeze as fast.
819865
Conservation of energy.\n\nCalculate the amount of heat stored in the 28ºC water using 0ºC as the starting point.  This energy must first melt the ice, for which you'll need to use the heat of fusion of water.  The remainder of the energy will warm up the entire amount of water.
980695
It depends on how much dry ice you have and what is the temp of the dry ice.
721040
I get 45.13 degree Celsius.\nReasoning:\nChanging 23 gram ice in water of 0 degree requires 7.66e3 Joule, according to part 1. This amount of energy taken from the 70 degree water decreases the temperature of the latter by 7.66e3 x (70-10) / 2.9e4 = 15.85 degrees (using part 1 and 2).\n\nSo now we have a mixture of 23 gram water at 0 degree and 115 gram (5 times as much!) at 54.15 degrees. This will average out to (5/6) x 54.15 = 45.13 degree Celcius.
590891
All matters dosnet expand on heat. Take ice, it shrinks or melts on heat. Hope you liked my short and sweet answwer.
963637
Gold's freezing point is 1064.58 degrees celsius.\n(This is the melting point and melting points are the same as freezing points.  Water, for example, melts at 0 degrees celsius but also freezes at 0 degrees celsius.)
332731
It doesn't always have to be.  The values for the heat of fusion of ice that you are using were probably found using equipment sensitive to only two significant figures.  I have seen heats of fusion values that have had more than two sig figs, but they were probably found with more sensitive equipment.
918553
Yes it can, but it will have a lower freezing point depending on the contents. It probably is lower than your freezer temp. Try using dry ice or liquid N
886956
It already has, or do you not read that all the worlds ice formations are melting at an alarming rate.  Usually when the ice melts in your freezer, it is getting to warm in there.
331795
your chemistry teacher probably wanted to know the + or - sign, then it should be + because when ice melts, it absorb heat to overcome the van der walls force between its molecules and ice also has high hydrogen bond between its molecules to overcomed. so, ice needs extra energy (heat) and the sign is positive. \nif he/she is asking bout the other sign, then it is the melting part. if heat is released, u can feel the heat on the surface of the material but if heat is absorbed, u can feel the coldness on its surface. if you hold ice in ur hand, it will melt more faster coz the ice absorbs heat from ur hand to overcome its force between bonds ( like i explain above)
629453
warm water dissolves ice faster than warm air because it can transfer and absorb heat faster than warm air of the same temperature