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Chemistry- Basic Energy Transfer Questions

  1. Jan 11, 2013 #1
    Why does no temperature change occur while ice is melting? Specifially, when very little ice is left, how does so much water remain at 0 degrees Celcius?

    Is the energy transfer (of heat) to ice constant? Specifically, does the time range in an exponential manner for different sizes of ice to melt? (Say a large chunk of ice is put over a flame. When it gets to be 1/6 of its original size form melting, does the liquid water surrounding the cube transfer more energy to the small cube because there is so much water to give energy that at the beginning of melting when there was less water?)

    When given the explanation "the heat energy breaks down the bonds that hold the particles together," what does "break down" mean? (Does the heat cause particles to move with so much force that they escape attraction, or does heat actually destroy some chemical bond holding solid water particles together?)

    Is the temperature of ice water an average of the liquid water and ice (i.e. ice = -0.5 degrees Celcius and water = 0.5 degrees Celcius) or are ice and water both have averages of 0 degrees Celcius and therefore average to 0 degrees?



    I thought about this stuff and looked online, but all answers were the same. I think velocity has to do with causing phase change, and I'm missing something in understanding the lack of temperature change. All I can think of is the liquid water particles collide with ice and transfer energy to ice causing ice to melt. But, them the melting times for different sizes of ice wouldn't be constant because with more ice melted, there would be more water to transfer energy, and then the small ice chunk would melt quicker. On the same point, chemistry equations and heating curves state otherwise.
    As for temperature, I think again the thermall energy form the liquid water particles would "transfer" to solid water particles, the solid then gaining phase energy.
    Anyone willing to help?
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Jan 12, 2013 #2

    Borek

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    Staff: Mentor

    Quite the opposite - smaller piece of ice gets less energy per unit of time than the large one, as as energy transfer takes place through the ice surface, and smaller piece has a smaller surface than the large one.

    Is there a difference between both scenarios?

    When we say the bath has a temperature of 0°C we refer to the equilibrium situation, when the amount of ice in the mixture is staying constant. As long as the ice is melting, water temperature can be not not zero. Otherwise, if they had both exactly the same temperature there would be by definition no energy transfer - so no melting would be possible.
     
  4. Jan 12, 2013 #3
    Thank you!
     
  5. Jan 12, 2013 #4
    The difference between scenarios is ice particles pull themselves apart compared to a bond "disintegrating" and then particles are free to separate.
     
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