In this lab you will calculate the energy required to change one gram of ice to water at its melting point (0 °C). This is also the energy that must be removed from one gram of water at its freezing to point to change it ice. This quantity is known as "the Specific Heat of Fusion of Ice," and has the symbol DHf,ice.
|lots of ice||2 thermometers|
Remember that the general formula for heat transferred is q = mDTCp
Also remember that when a warmer material is in contact with a cooler one, heat flows from the warmer to the cooler until they are the same temperature. Assuming these two materials are in contact with nothing else, then the quantity of heat lost by the warm stuff (qwarm) must be exactly equal and opposite to the quantity of heat gained by the cool stuff (qcool). This lab examines the extra step: since the cool thing had to melt first, then qwarm is equal to the heat needed to melt the ice PLUS the heat needed to warm up up the newly liquid water (qmelt + qcool).
qmelt + qwarm up + qcool down = 0
For each trial, use your data to calculate qmelt
and DHf, ice (which is
Calculate an average DHf, ice.
Look up the accepted value of DHf, ice.
Calculate your average % error.
Remember to show all labels and calculations!
[Heat of Fusion of Ice score sheet][MHS Chem page]