Chemistry Cooling curve question!?
The graph is a cooling curve for naphthalene in the liquid phase.
★What is the significance of the flat portion of your graph?
★Why does the temperature stop falling for several minutes?
Thanks for all the help! :)
The graph is here: http://www.flickr.com/photos/62019456@N08/5635942397/in/photostream
The graph is a cooling curve for naphthalene in the liquid phase.
★What is the significance of the flat portion of your graph?
★Why does the temperature stop falling for several minutes?
Thanks for all the help! :)
The graph is here: http://www.flickr.com/photos/62019456@N08/5635942397/in/photostream
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You should be able to observe crystallization happening during the flat part of the cooling curve. The temp at which that is happening is the freezing point of the substance.
The temp stops falling because the act of crystallizing is an exothermic process and is releasing heat. This keeps the temperature pretty constant until all the liquid has solidified.
The temp stops falling because the act of crystallizing is an exothermic process and is releasing heat. This keeps the temperature pretty constant until all the liquid has solidified.