grr i cant find the answer to this problem. here it is:
A well-stirred mixture of ice and water is at equilibrium. If a small amount of warm water or ice is added, the temperature doesn't change why?
2006-12-17 12:57:02 · 2 answers · asked by shannon w 3 in Science & Mathematics ➔ Chemistry
Hi, here is a good reference site that explains liquid - solid and gas phase equilibrium for a pure substance. Water is listed as an example on this page and the peculiar trait that ice is less dense than water is noted in the phase diagram. (But, that has nothing to do with your question). Assuming that the pressure of this experiment has not changed (I'm sure normal atmospheric pressure is applied in your example) the temperature of this system will not change because the equilibrium between ice and water only occurs at one temperature (32oF or 0oC). Adding more ice or more water won't change the temperature of the ice water because ice water can only have one temperature. Imagine if the temperature of the system dropped dramatically - you would have a solid block of ice, no more water. Or, if you added a lot of heat and melted all the ice you would have water but no more ice, then the water would gradually heat up. Keep adding heat and obviously the water will turn into vapor (gas form of water molecules). If you look at the phase diagram, you will notice that ice can turn directly into vapor. This is called "sublimation". Sublimation is cool. Have you ever put a tray of ice in the freezer and left it in there for a LONG time? Like months and months? What you will see is that gradually the ice "disappears". It sublimates to gas vapors and "floats away". Cool! Keep in mind that if you add another chemical to this system (like SALT for example or alcohol), you will change the dynamics and the temperature may change.
2006-12-17 13:21:04 · answer #1 · answered by Elizabeth P 2 · 0⤊ 0⤋
It is because of the types of internal energy. When you melt ice first you have to raise the potential energy so even as you add energy it won;t raise in temperature until it is completly melted. ANd same with freezing water it will go to 0 C and then will stay at zero until frozen. Sooo if you added warm water the ice would start to melt as potential energy in the ice increases but if it isn't enough energy then kinetic ( temperature) wouldnt be able to rise, and vise vera with adding ice the potential energy of the water would decrease but not enough so temperature can go down
2006-12-17 21:14:40 · answer #2 · answered by Ravioli 2 · 0⤊ 0⤋